Use wxDELETE() and wxDELETEA() when possible.

Use wxDELETE[A]() functions which automatically NULL out their arguments after
deleting them instead of doing it manually.

Closes #9685.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@64656 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/ipc/baseclient.cpp

@@ -184,8 +184,7 @@ void MyClient::Disconnect()
     if (m_connection)
     {
         m_connection->Disconnect();
-        delete m_connection;
-        m_connection = NULL;
+        wxDELETE(m_connection);
         wxLogMessage("Client disconnected from server");
     }
     wxGetApp().ExitMainLoop();