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

src/common/ftp.cpp

@@ -203,8 +203,7 @@ wxSocketBase *wxFTP::AcceptIfActive(wxSocketBase *sock)
     {
         m_lastError = wxPROTO_CONNERR;
         wxLogError(_("Timeout while waiting for FTP server to connect, try passive mode."));
-        delete sock;
-        sock = NULL;
+        wxDELETE(sock);
     }
     else
     {