lib-lda: Don't crash if remote disconnects during sending mail via LMTP.
lib-lda: Don't crash if remote disconnects during sending mail via LMTP.

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