Sets wasm_worning_as_error disabled by default. (#1406)

This removes `-Werror` set by default, thus conforming with default
bazel cc toolchain.

Co-authored-by: William Izzo <william.izzo@hey.com>

bazel/emscripten_toolchain/toolchain.bzl

diff --git a/bazel/emscripten_toolchain/toolchain.bzl b/bazel/emscripten_toolchain/toolchain.bzl
index 5a03ada..c3c9f43 100644
--- a/bazel/emscripten_toolchain/toolchain.bzl
+++ b/bazel/emscripten_toolchain/toolchain.bzl
@@ -445,7 +445,7 @@
         ),
         feature(
             name = "wasm_warnings_as_errors",
-            enabled = True,
+            enabled = False,
         ),
 
         # ASan and UBSan. See also: