Crash if no Kerberos credential cache found
One of my Jabber accounts allows authorisation via Kerberos. Since updating Gajim I can now sign in without needing password, but if I haven't requested a Kerberos token yet then sign in fails with the 'A programming error has been detected' popup (the traceback is attached). The account is then stuck in the 'Connecting' state until a Kerberos token is obtained and either Gajim is restarted or the account is cycled through 'Offline'.
I assume that this should fall back to password authorisation if GSSAPI authorisation fails. If I was unable to request a Kerberos token for the site then I would have no way of signing in to this account.