removed unused wxWindowGTK::m_isFrame

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@15719 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/toplevel.cpp

@@ -298,7 +298,6 @@ void wxTopLevelWindowGTK::Init()
     m_miniTitle = 0;
     m_mainWidget = (GtkWidget*) NULL;
     m_insertInClientArea = TRUE;
-    m_isFrame = TRUE;
     m_isIconized = FALSE;
     m_fsIsShowing = FALSE;
     m_themeEnabled = TRUE;