1. reset default item in ~wxWindow (better to be safe)

2. blind fix for Motif compilation


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@11377 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/motif/button.cpp

@@ -110,8 +110,7 @@ bool wxButton::Create(wxWindow *parent, wxWindowID id, const wxString& label,
 void wxButton::SetDefault()
 {
     wxWindow *parent = GetParent();
-    wxPanel *panel = wxDynamicCast(parent, wxPanel);
-    if ( panel )
+    if ( parent )
         panel->SetDefaultItem(this);
 
     // We initially do not set XmNdefaultShadowThickness, to have small buttons.