call OnInit() from all samples to allow using standard command line options with all of them (patch 1623971)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@44354 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/regtest/regtest.cpp

@@ -318,6 +318,9 @@ IMPLEMENT_APP(RegApp)
 // `Main program' equivalent, creating windows and returning main app frame
 bool RegApp::OnInit()
 {
+    if ( !wxApp::OnInit() )
+        return false;
+
     // create the main frame window and show it
     RegFrame *frame = new RegFrame(NULL, _T("wxRegTest"), 50, 50, 600, 350);
     frame->Show(true);