avoid GCC warning "suggest braces around empty body in an ‘else’ statement"

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67410 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/menu.cpp

@@ -601,7 +601,9 @@ void wxMenuItem::SetBitmap(const wxBitmap& bitmap)
     if (m_kind == wxITEM_NORMAL)
         m_bitmap = bitmap;
     else
+    {
         wxFAIL_MSG("only normal menu items can have bitmaps");
+    }
 }
 
 void wxMenuItem::Check( bool check )