Fix an oversight

Commit ff256956 introduced a frame_clock_events_paused
flag, but only ever set it to TRUE, instead of unsetting it when
events are resumed. This was leading to assertion failures in
_gdk_display_unpause_events().

gdk/gdkwindow.c

@@ -10942,7 +10942,7 @@ gdk_window_resume_events (GdkFrameClock *clock,
   display = gdk_window_get_display (window);
   _gdk_display_unpause_events (display);
 
-  window->frame_clock_events_paused = TRUE;
+  window->frame_clock_events_paused = FALSE;
 }
 
 static void
@@ -10976,9 +10976,7 @@ gdk_window_set_frame_clock (GdkWindow     *window,
   if (window->frame_clock)
     {
       if (window->frame_clock_events_paused)
-        {
-          gdk_window_resume_events (window->frame_clock, G_OBJECT (window));
-        }
+        gdk_window_resume_events (window->frame_clock, G_OBJECT (window));
 
       g_signal_handlers_disconnect_by_func (G_OBJECT (window->frame_clock),
                                             G_CALLBACK (gdk_window_flush_events),