mail/py-milter: fix runtime crash; pass on MAINTAINER
- Import patch to resolve crash during IPv6 connection handling. Submitter
has coordinated fix with upstream; it can be removed next update.
- Pass on MAINTAINER to from ports@ to submitter.
- While here, move DIST_SUBDIR to appease portlint.
Submitted by: email@example.com
MFH: 2016Q4 (blanket)