gl/cocoa: Fix compiler warning

gstglwindow_cocoa.m: In function '-[GstGLNSView drawRect:]':
gstglwindow_cocoa.m:555: warning: 'GstGLNSView' may not respond to '-reshape'
gstglwindow_cocoa.m:555: warning: (Messages without a matching method signature
gstglwindow_cocoa.m:555: warning: will be assumed to return 'id' and accept
gstglwindow_cocoa.m:555: warning: '...' as arguments.)

gst-libs/gst/gl/cocoa/gstglwindow_cocoa.m

@@ -552,10 +552,10 @@ resize_cb (gpointer data)
 }
 
 - (void)drawRect: (NSRect)dirtyRect {
-  [self reshape];
+  [self reshape:nil];
 }
 
-- (void)reshape {
+- (void)reshape: (NSNotification*)notification {
   GstGLWindow *window;
 
   window = GST_GL_WINDOW (window_cocoa);