Fix #2720 for master also. Finally that's not an hack as the code is build to

stop the playlist just after removing the playing item (so that's ok to stop
the PL even when it's empty).

(cherry picked from commit be1f4305)
Signed-off-by: Rémi Duraffort <ivoire@videolan.org>

src/playlist/control.c

@@ -104,7 +104,7 @@ static int PlaylistVAControl( playlist_t * p_playlist, int i_query, va_list args
     if( !vlc_object_alive( p_playlist ) )
         return VLC_EGENERIC;
 
-    if( playlist_IsEmpty( p_playlist ) )
+    if( playlist_IsEmpty( p_playlist ) && i_query != PLAYLIST_STOP )
         return VLC_EGENERIC;
 
     switch( i_query )