Fixed saving GIFs on big-endian architectures.

Word (16 bits) values were written in the wrong order resulting in invalid GIF files on for example PowerPC machines.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67802 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/imaggif.cpp

@@ -643,7 +643,7 @@ bool wxGIFHandler_WriteWord(wxOutputStream *stream, wxUint16 word)
 
     buf[0] = word & 0xff;
     buf[1] = (word >> 8) & 0xff;
-    return wxGIFHandler_Write(stream, &word, sizeof(word));
+    return wxGIFHandler_Write(stream, &buf, sizeof(buf));
 }
 
 bool wxGIFHandler_WriteHeader(wxOutputStream *stream, int width, int height,