Update to 2.4.1
    
    - New upstream release 2.4.1
      - Fix a security flaw (GH#1175, CVE-2018-7750) in Paramiko's server mode
        (this does not impact client use) where authentication status was not
        checked before processing channel-open and other requests typically only
        sent after authenticating
      - Ed25519 auth key decryption raised an unexpected exception when given a
        unicode password string (typical in python 3) (GH#1039)