logging: Log exception name also in auth_complete.
logging: Log exception name also in auth_complete.

`HTTPError` has empty string for `str(HTTPError())`. Logging it
as it is would not be much helpful. So, this commits adds code
to log the name of error also.

andersk/zulip,eeshangarg/zulip,showell/zulip,punchagan/zulip,rht/zulip,brainwane/zulip,shubhamdhama/zulip,hackerkid/zulip,timabbott/zulip,synicalsyntax/zulip,andersk/zulip,kou/zulip,kou/zulip,shubhamdhama/zulip,showell/zulip,brainwane/zulip,eeshangarg/zulip,showell/zulip,timabbott/zulip,showell/zulip,zulip/zulip,punchagan/zulip,brainwane/zulip,timabbott/zulip,showell/zulip,andersk/zulip,zulip/zulip,synicalsyntax/zulip,showell/zulip,punchagan/zulip,rht/zulip,timabbott/zulip,synicalsyntax/zulip,andersk/zulip,andersk/zulip,hackerkid/zulip,brainwane/zulip,punchagan/zulip,eeshangarg/zulip,eeshangarg/zulip,kou/zulip,brainwane/zulip,zulip/zulip,eeshangarg/zulip,punchagan/zulip,timabbott/zulip,brainwane/zulip,andersk/zulip,shubhamdhama/zulip,rht/zulip,shubhamdhama/zulip,synicalsyntax/zulip,brainwane/zulip,synicalsyntax/zulip,hackerkid/zulip,shubhamdhama/zulip,shubhamdhama/zulip,andersk/zulip,punchagan/zulip,zulip/zulip,synicalsyntax/zulip,rht/zulip,kou/zulip,zulip/zulip,punchagan/zulip,hackerkid/zulip,shubhamdhama/zulip,rht/zulip,showell/zulip,rht/zulip,kou/zulip,hackerkid/zulip,eeshangarg/zulip,kou/zulip,synicalsyntax/zulip,zulip/zulip,eeshangarg/zulip,timabbott/zulip,hackerkid/zulip,rht/zulip,zulip/zulip,hackerkid/zulip,kou/zulip,timabbott/zulip