Remove connection of MyDllApp::OnIdle() handler in the dll sample.

This method didn't really exist, the code only worked because it connected to
wxApp::OnIdle() which exists in wxMSW but not the other ports.

Simply remove the apparently unnecessary call.

See #13902.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73289 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/dll/my_dll.cpp

@@ -148,7 +148,6 @@ MyDllApp::MyDllApp()
     // by shutting the thread down when it's no longer needed, though.
     SetExitOnFrameDelete(false);
 
-    Connect(wxEVT_IDLE, wxIdleEventHandler(MyDllApp::OnIdle));
     Connect(CMD_SHOW_WINDOW,
             wxEVT_THREAD,
             wxThreadEventHandler(MyDllApp::OnShowWindow));