Revert 'Possible fix for Mac library issue.'.

The ',' on the end of the data was not creating a rogue zero entry.
So adding ImageSize-- was incorrect.

src/Theme.cpp

@@ -985,8 +985,6 @@ bool ThemeBase::ReadImageCache( teThemeType type, bool bOkIfNotFound)
             pImage = HiContrastImageCacheAsData;
             break;
       }
-      // The image size includes a rogue '0' on the end, because the array ends in a ','.
-      ImageSize--;
       //wxLogDebug("Reading ImageCache %p size %i", pImage, ImageSize );
       wxMemoryInputStream InternalStream( pImage, ImageSize );