Don't show windows with "hidden" XRC attribute at all.

This is better than showing them initially and then hiding them if only
because it avoids the unexpected wxEVT_SHOW events being generated.

Closes #15919.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75757 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/xrc/xmlres.cpp

@@ -2440,8 +2440,6 @@ void wxXmlResourceHandlerImpl::SetupWindow(wxWindow *wnd)
         wnd->Enable(false);
     if (GetBool(wxT("focused"), 0) == 1)
         wnd->SetFocus();
-    if (GetBool(wxT("hidden"), 0) == 1)
-        wnd->Show(false);
 #if wxUSE_TOOLTIPS
     if (HasParam(wxT("tooltip")))
         wnd->SetToolTip(GetText(wxT("tooltip")));