Gong exits with cryptic error on SSH login failure

On Cisco IOS in some cases (perhaps OS version):

    Connecting to device1.  Use ^X to exit.
    
    Fetching credentials from /home/jathan/.tacacsrc
    
    Connection failed for the following reason:
    
    Protocol error: expected packet type 61, got 50
    
    BYE

Reference: https://supportforums.cisco.com/thread/175941

> Most likely the router disconnected unexpectedly.  Packet 50 (in SSHv2) is 
> SSH2_MSG_USERAUTH_REQUEST, meaning request for user authentication.
> Sometimes, if the credentials are wrong, IOS immediately disconnects instead of
> letting you try again

This should be detected as a login failure by Trigger and prompt you to fix your credentials.