Replaced kludgy input_first variable with just checking if input stream's offset is 0.
Replaced kludgy input_first variable with just checking if input stream's
offset is 0.

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