Remove tree control lines unconditionally under

GTK2 (similar to what wxMac does) as it simply
    looks wrong (as we are using GTK+ tree buttons).


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@42004 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/treectlg.cpp

@@ -820,6 +820,9 @@ bool wxGenericTreeCtrl::Create(wxWindow *parent,
     if (major < 10)
         style |= wxTR_ROW_LINES;
 #endif // __WXMAC__
+#ifdef __WXGTK20__
+    style |= wxTR_NO_LINES;
+#endif
 
     if ( !wxControl::Create( parent, id, pos, size,
                              style|wxHSCROLL|wxVSCROLL,