macosx: Don't re-center extensions on every dialog update

If the user has moved the extension dialog, we don't want to re-center it on every single update -- many extensions update their dialogs on every input change, and this behavior can cause the extension dialog to keep re-overlapping with the video, which is very frustrating.
Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>

modules/gui/macosx/ExtensionsDialogProvider.m

@@ -539,10 +539,8 @@ static ExtensionsDialogProvider *_o_sharedInstance = nil;
         [dialogWindow setHas_lock:NO];
 
         BOOL visible = !p_dialog->b_hide;
-        if (visible) {
-            [dialogWindow center];
+        if (visible)
             [dialogWindow makeKeyAndOrderFront:self];
-        }
         else
             [dialogWindow orderOut:nil];
     }