Suppress harmless warning about unhandled wxSHOW_EFFECT_NONE.

wxNonOwnedWindowImpl::ShowWithEffect() is not supposed to be called with
wxSHOW_EFFECT_NONE effect so assert if it is.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62404 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/osx/carbon/nonownedwnd.cpp

@@ -1419,6 +1419,11 @@ bool wxNonOwnedWindowCarbonImpl::ShowWithEffect(bool show,
                 transition = kWindowZoomTransitionEffect;
             break;
 
+        case wxSHOW_EFFECT_NONE:
+            // wxNonOwnedWindow is supposed to call Show() itself in this case
+            wxFAIL_MSG( "ShowWithEffect() shouldn't be called" );
+            return false;
+
         case wxSHOW_EFFECT_MAX:
             wxFAIL_MSG( "invalid effect flag" );
             return false;