Fix GitHub repo url in emsdk_manifest.json (#757)

It was still using the old repo location which was moved to the emscripten-core organization.
diff --git a/emsdk_manifest.json b/emsdk_manifest.json
index b556fbc..379545a 100644
--- a/emsdk_manifest.json
+++ b/emsdk_manifest.json
@@ -34,10 +34,10 @@
     "version": "tag-e%tag%",
     "bitness": 32,
     "append_bitness": false,
-    "windows_url": "https://github.com/kripken/emscripten-fastcomp/archive/%tag%.zip",
-    "unix_url": "https://github.com/kripken/emscripten-fastcomp/archive/%tag%.tar.gz",
-    "windows_clang_url": "https://github.com/kripken/emscripten-fastcomp-clang/archive/%tag%.zip",
-    "unix_clang_url": "https://github.com/kripken/emscripten-fastcomp-clang/archive/%tag%.tar.gz",
+    "windows_url": "https://github.com/emscripten-core/emscripten-fastcomp/archive/%tag%.zip",
+    "unix_url": "https://github.com/emscripten-core/emscripten-fastcomp/archive/%tag%.tar.gz",
+    "windows_clang_url": "https://github.com/emscripten-core/emscripten-fastcomp-clang/archive/%tag%.zip",
+    "unix_clang_url": "https://github.com/emscripten-core/emscripten-fastcomp-clang/archive/%tag%.tar.gz",
     "custom_install_script": "build_fastcomp",
     "activated_path": "%installation_dir%/%fastcomp_build_bin_dir%",
     "activated_cfg": "LLVM_ROOT='%installation_dir%/%fastcomp_build_bin_dir%'",
@@ -49,10 +49,10 @@
     "version": "tag-e%tag%",
     "bitness": 64,
     "append_bitness": false,
-    "windows_url": "https://github.com/kripken/emscripten-fastcomp/archive/%tag%.zip",
-    "unix_url": "https://github.com/kripken/emscripten-fastcomp/archive/%tag%.tar.gz",
-    "windows_clang_url": "https://github.com/kripken/emscripten-fastcomp-clang/archive/%tag%.zip",
-    "unix_clang_url": "https://github.com/kripken/emscripten-fastcomp-clang/archive/%tag%.tar.gz",
+    "windows_url": "https://github.com/emscripten-core/emscripten-fastcomp/archive/%tag%.zip",
+    "unix_url": "https://github.com/emscripten-core/emscripten-fastcomp/archive/%tag%.tar.gz",
+    "windows_clang_url": "https://github.com/emscripten-core/emscripten-fastcomp-clang/archive/%tag%.zip",
+    "unix_clang_url": "https://github.com/emscripten-core/emscripten-fastcomp-clang/archive/%tag%.tar.gz",
     "custom_install_script": "build_fastcomp",
     "activated_path": "%installation_dir%/%fastcomp_build_bin_dir%",
     "activated_cfg": "LLVM_ROOT='%installation_dir%/%fastcomp_build_bin_dir%'",
@@ -64,8 +64,8 @@
     "version": "master",
     "bitness": 32,
     "install_path": "clang/fastcomp",
-    "url": "https://github.com/kripken/emscripten-fastcomp.git",
-    "clang_url": "https://github.com/kripken/emscripten-fastcomp-clang.git",
+    "url": "https://github.com/emscripten-core/emscripten-fastcomp.git",
+    "clang_url": "https://github.com/emscripten-core/emscripten-fastcomp-clang.git",
     "git_branch": "master",
     "custom_install_script": "build_fastcomp",
     "activated_path": "%installation_dir%/%fastcomp_build_bin_dir%",
@@ -79,8 +79,8 @@
     "bitness": 64,
     "install_path": "clang/fastcomp",
     "git_branch": "master",
-    "url": "https://github.com/kripken/emscripten-fastcomp.git",
-    "clang_url": "https://github.com/kripken/emscripten-fastcomp-clang.git",
+    "url": "https://github.com/emscripten-core/emscripten-fastcomp.git",
+    "clang_url": "https://github.com/emscripten-core/emscripten-fastcomp-clang.git",
     "custom_install_script": "build_fastcomp",
     "activated_path": "%installation_dir%/%fastcomp_build_bin_dir%",
     "activated_cfg": "LLVM_ROOT='%installation_dir%/%fastcomp_build_bin_dir%'",
@@ -331,8 +331,8 @@
     "version": "tag-%tag%",
     "bitness": 32,
     "append_bitness": false,
-    "windows_url": "https://github.com/kripken/emscripten/archive/%tag%.zip",
-    "unix_url": "https://github.com/kripken/emscripten/archive/%tag%.tar.gz",
+    "windows_url": "https://github.com/emscripten-core/emscripten/archive/%tag%.zip",
+    "unix_url": "https://github.com/emscripten-core/emscripten/archive/%tag%.tar.gz",
     "zipfile_prefix": "emscripten-e",
     "activated_cfg": "EMSCRIPTEN_ROOT='%installation_dir%';EMSCRIPTEN_NATIVE_OPTIMIZER='%installation_dir%%generator_prefix%_32bit_optimizer/%cmake_build_type_on_win%optimizer%.exe%'",
     "activated_path": "%installation_dir%",
@@ -347,8 +347,8 @@
     "version": "tag-%tag%",
     "bitness": 64,
     "append_bitness": false,
-    "windows_url": "https://github.com/kripken/emscripten/archive/%tag%.zip",
-    "unix_url": "https://github.com/kripken/emscripten/archive/%tag%.tar.gz",
+    "windows_url": "https://github.com/emscripten-core/emscripten/archive/%tag%.zip",
+    "unix_url": "https://github.com/emscripten-core/emscripten/archive/%tag%.tar.gz",
     "activated_cfg": "EMSCRIPTEN_ROOT='%installation_dir%';EMSCRIPTEN_NATIVE_OPTIMIZER='%installation_dir%%generator_prefix%_64bit_optimizer/%cmake_build_type_on_win%optimizer%.exe%'",
     "activated_path": "%installation_dir%",
     "activated_env": "EMSCRIPTEN=%installation_dir%;EMSCRIPTEN_NATIVE_OPTIMIZER=%installation_dir%%generator_prefix%_64bit_optimizer/%cmake_build_type_on_win%optimizer%.exe%",
@@ -360,8 +360,8 @@
   {
     "id": "emscripten",
     "version": "%precompiled_tag%",
-    "windows_url": "https://github.com/kripken/emscripten/archive/%precompiled_tag%.zip",
-    "unix_url": "https://github.com/kripken/emscripten/archive/%precompiled_tag%.tar.gz",
+    "windows_url": "https://github.com/emscripten-core/emscripten/archive/%precompiled_tag%.zip",
+    "unix_url": "https://github.com/emscripten-core/emscripten/archive/%precompiled_tag%.tar.gz",
     "activated_cfg": "EMSCRIPTEN_ROOT='%installation_dir%'",
     "activated_path": "%installation_dir%",
     "activated_env": "EMSCRIPTEN=%installation_dir%"