Revert "Qt4: --embedded-video must be checked on the window object (not the UI)"

This reverts commit 4c40aec4.

We already check is_standalone.

modules/gui/qt4/qt4.cpp

@@ -542,8 +542,6 @@ static int WindowOpen( vlc_object_t *p_obj )
     if( var_InheritBool( p_obj, "video-wallpaper" ) )
         return VLC_EGENERIC;
 #endif
-    if( !var_InheritBool( p_obj, "embedded-video" ) )
-        return VLC_EGENERIC;
 
     vlc_value_t val;
     if( var_Inherit( p_obj, "qt4-iface", VLC_VAR_ADDRESS, &val ) )