Upgrade net/miniupnpd from 2.0.20180503 to 2.1.20190210

Add a patch to unbreak port when CHECK_PORTINUSE option
is activated. The issue was caussed by changes in the
structures xtcpcb and xinpcb returned by the kernel after
r315662. The fix was inspired by changes made in
usr.bin/systat/netstat.c tool.

The patch was submitted to the upstream project and
merged : https://github.com/miniupnp/miniupnp/pull/353

PR: 236173
Reported by: Igor Pavlov <igor.arabesc.pavlov@gmail.com>
Approved by: Tor Halvard Furulund <squat@squat.no> (maintainer)