pidgin/pidgin

IRCv3: Set the SASL login name to the current nick if not set during connection

This _should_ help users make sure they authenticate as the correct user. They
are still able to manually specify a SASL Login Name, but if it isn't set when
a connection is attempted, it will be set to the nick defined on the account.

This should also fix the scenario where a user is adding the account to Pidgin
but already has the same account connected because the login name will be the
nick they entered not the one that's chosen if there's a nick collision.

Testing Done:
Connected an IRCv3 account with the `SASL Login Name` unset and verified it was set after connecting. Then set the `SASL Login Name` to something else, attempted connection, verified a SASL failure and verified that the `SASL Login Name` changed persisted.

Reviewed at https://reviews.imfreedom.org/r/2329/
Björn Voigt <bjoernv@arcor.de> Björn Voigt <bjoern@cs.tu-berlin.de>
Björn Voigt <bjoernv@arcor.de> Bjoern Voigt <bjoern@cs.tu-berlin.de>
David Woodhouse <dwmw2@infradead.org> <David.Woodhouse@intel.com>
David Woodhouse <dwmw2@infradead.org> <dwmw@amazon.co.uk>
David Woodhouse <dwmw2@infradead.org> dwmw2 <dwmw2@infradead.org>
# not sure how to make this one work because this doesn't do it..
dequis <dx@dxzone.com.ar> dequis <dx@dxzone.com.ar
dequis <dx@dxzone.com.ar> dx <dx@dxzone.com.ar>
Eion Robb <eion@robbmob.com> Eion Robb <eionrobb@gmail.com>
Elliott Sales de Andrade <quantum.analyst@gmail.com> Elliott Sales de Andrade <qulogic@pidgin.im>
Elliott Sales de Andrade <quantum.analyst@gmail.com> Elliott S <quantum.analyst@gmail.com>
Ethan Blanton <elb@pidgin.im> Ethan Blanton <elb@fiji-systems.com>
Ethan Blanton <elb@pidgin.im> Ethan Blanton <elb@kb8ojh.net>
Gary Kramlich <grim@reaperworld.com> <grim@pidgin.im>
Jerin Philip <monu1618@gmail.com> Jerin Philip <jerin.philip@students.iiit.ac.in>
Jonathan Champ <jrchamp@ncsu.edu> Jonathan Champ <royanee@users.sourceforge.net>
Jorge Villaseñor <salinasv@pidgin.im> Jorge Villaseñor <masca@cpw.pidgin.im>
Mark Doliner <mark@kingant.net> Mark Doliner <markdoliner@pidgin.im>
Matěj Cepl <mcepl@cepl.eu> Matěj Cepl <mcepl@redhat.com>
Michael McConville <mmcconville@mykolab.com> Michael McConville <mmcco@mykolab.com>
Michael McConville <mmcconville@mykolab.com> mmcconville@mykolab.com
Mike Ruprecht <cmaiku@gmail.com> Michael Ruprecht <maiku@pidgin.im>
Richard Laager <rlaager@wiktel.com> Richard Laager <rlaager@pidgin.im>
Robert Vehse <robertvehse@fastmail.fm> Robbie <robertvehse@fastmail.fm>
Shalom Craimer <scraimer@gmail.com> Shalom Craimer <s.transifex2015@craimer.org>
Tomasz Wasilczyk <twasilczyk@pidgin.im> Tomasz Wasilczyk <tomkiewicz@cpw.pidgin.im>
Yngve Spjeld Landro <l10n@landro.net> Yngve Spjeld Landro <nynorsk@strilen.net>