lib-ssl-iostream: Error handling fix. Don't set last_error="(null)" when the connection was simply disconnected.
lib-ssl-iostream: Error handling fix.
Don't set last_error="(null)" when the connection was simply disconnected.

LTD-Beget/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot