Updated o_stream_send_istream() comments
Updated o_stream_send_istream() comments

damoxc/dovecot,damoxc/dovecot,damoxc/dovecot,damoxc/dovecot,Distrotech/dovecot,damoxc/dovecot,Distrotech/dovecot,Distrotech/dovecot,Distrotech/dovecot,Distrotech/dovecot