Updated mbox_dirty_syncs and mbox_lazy_writes comments.
Updated mbox_dirty_syncs and mbox_lazy_writes comments.

damoxc/dovecot,Distrotech/dovecot,Distrotech/dovecot,LTD-Beget/dovecot,damoxc/dovecot,damoxc/dovecot,Distrotech/dovecot,LTD-Beget/dovecot,damoxc/dovecot,Distrotech/dovecot,damoxc/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot,Distrotech/dovecot,LTD-Beget/dovecot