Make the ErrorManager work without config.

Errors that happen before the IdentityManager is configured
are useful to be able to see.

Change-Id: Iad6c54182aa101528e8bb2169ed08249f650f39c
Reviewed-on: http://gerrit.dmdirc.com/2827
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Automatic-Compile: DMDirc Build Manager