macosx: only set videoplayback to false when last vout window closes

For instance, when we disable visualisations, the playback isn't finished yet,
necessarily.

modules/gui/macosx/VLCVoutWindowController.m

@@ -168,6 +168,9 @@
 
     [[o_window videoView] releaseVoutThread];
     [o_vout_dict removeObjectForKey:o_key];
+
+    if ([o_vout_dict count] == 0)
+        [[VLCMain sharedInstance] setActiveVideoPlayback:NO];
 }
 
 - (void)updateWindowsControlsBarWithSelector:(SEL)aSel

modules/gui/macosx/intf.m

@@ -240,7 +240,6 @@ static int WindowControl(vout_window_t *p_wnd, int i_query, va_list args)
 void WindowClose(vout_window_t *p_wnd)
 {
     NSAutoreleasePool *o_pool = [[NSAutoreleasePool alloc] init];
-    [[VLCMain sharedInstance] setActiveVideoPlayback:NO];
 
     [[[VLCMain sharedInstance] voutController] performSelectorOnMainThread:@selector(removeVoutforDisplay:) withObject:[NSValue valueWithPointer:p_wnd] waitUntilDone:NO];