Reset m_request.isKeepAlive to true if responseCode == 301
during renaming a directory. Otherwise the connection is gone
and renaming fails, if the server is configured 'KeepAlive off'.
After sending the not quite correct request 'MOVE dirurl'
without trailing '/', an Apache webserver answers with a
redirection (301) providing the correct dirurl with trailing
'/'. But in this case the session is not reset, so if the
server sets isKeepAlive to false the connection is ended