net/subnetcalc: Update 2.6.6 => 2.7.1

This new version provides several improvements:

• Replaced deprecated libGeoIP by libMaxMindDB. This particularly again allows GeoIP support under FreeBSD. Optionally, GeoIP support can be disabled.
• IDN is now supported under FreeBSD as well.
• I18N support is configurable.

Changelog:
https://github.com/dreibh/subnetcalc/blob/subnetcalc-2.7.1/ChangeLog

Commit log:
https://github.com/dreibh/subnetcalc/compare/subnetcalc-2.6.6...subnetcalc-2.7.1

PR: 295695
Sponsored by: UNIS Labs