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/minifram/minifram.cpp

@@ -57,6 +57,9 @@ wxButton      *button     = (wxButton*) NULL;
 // main frame
 bool MyApp::OnInit()
 {
+  if ( !wxApp::OnInit() )
+    return false;
+
   // Create the main frame window
   main_frame = new MyMainFrame((wxFrame *) NULL, wxID_ANY, _T("wxFrame sample"),
      wxPoint(100, 100), wxSize(300, 200));