skins2: don't resize video if set up not to do so.

This bug has become more conspicuous in vlc1.2, because of some enhancement in
 the vout reuse (width/height no longer a limitation)
(cherry picked from commit 9346f23dd752eabf9c79bb588c267314d3fe34d9)

modules/gui/skins2/controls/ctrl_video.cpp

@@ -122,6 +122,9 @@ void CtrlVideo::unsetLayout()
 
 void CtrlVideo::resizeControl( int width, int height )
 {
+    if( !m_bAutoResize )
+        return;
+
     WindowManager &rWindowManager =
         getIntf()->p_sys->p_theme->getWindowManager();