skins2: correct a uri conversion issue with new vlc_path2uri

new vlc_path2uri function now expects a valid not-yet-converted file name.

This fixes art display errors with latest vlc from current git rep.

modules/gui/skins2/src/file_bitmap.cpp

@@ -43,10 +43,16 @@ FileBitmap::FileBitmap( intf_thread_t *pIntf, image_handler_t *pImageHandler,
     video_format_Init( &fmt_in, 0 );
     video_format_Init( &fmt_out, VLC_CODEC_RGBA );
 
-    char* psz_uri = vlc_path2uri( fileName.c_str(), NULL );
-    pPic = image_ReadUrl( pImageHandler, psz_uri, &fmt_in, &fmt_out );
-    free( psz_uri );
+    if( strstr( fileName.c_str(), "://" ) == NULL )
+    {
+        char *psz_uri = vlc_path2uri( fileName.c_str(), NULL );
+        if( !psz_uri )
+            return;
+        fileName = psz_uri;
+        free( psz_uri );
+    }
 
+    pPic = image_ReadUrl( pImageHandler, fileName.c_str(), &fmt_in, &fmt_out );
     if( !pPic )
         return;