Handle muxed connections in resolvePraefectAddress
With muxed connections, authInfo is never nil. If no transport security is needed, it is set to the 'insecure' transport credentials. resolvePraefectAddress was not taking the transport security type into account and failed when Gitaly was contacted over an insecure muxed TCP connection. This commit fixes the problem by handling the insecure muxed connection case as it does without the multiplexing.
Edited by Sami Hiltunen