mail storage service: If chdir() fails with EACCES, give a better error message.
mail storage service: If chdir() fails with EACCES, give a better error message.

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