More HTTPS changes in the documentation.
diff --git a/README-SDL.txt b/README-SDL.txt
index c3d2d37..2984b14 100644
--- a/README-SDL.txt
+++ b/README-SDL.txt
@@ -6,7 +6,7 @@
 and emulators.

 

 The Simple DirectMedia Layer library source code is available from:

-http://www.libsdl.org/

+https://www.libsdl.org/

 

 This library is distributed under the terms of the zlib license:

 http://www.zlib.net/zlib_license.html