winemac: Remove a window from the NSWorkspace notification center when it's deallocated.

It was added as an observer in commit 3beec95a0.  Failing to remove it caused
the notification center to have a dangling pointer and caused crashes and hangs.

Signed-off-by: Ken Thomases <ken@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

dlls/winemac.drv/cocoa_window.m

@@ -777,6 +777,7 @@ + (WineWindow*) createWindowWithFeatures:(const struct macdrv_window_features*)w
 
     - (void) dealloc
     {
+        [[[NSWorkspace sharedWorkspace] notificationCenter] removeObserver:self];
         [[NSNotificationCenter defaultCenter] removeObserver:self];
         [queue release];
         [latentChildWindows release];