net-im/freetalk: update to version 4.1

Changelog: https://github.com/GNUFreetalk/freetalk/releases

Port Changes:

• switch to GitHub for distfile
• include license information
• other miscellaneous changes

PR: 213777
Submitted by: olevole@olevole.ru (maintainer)
Approved by: AMDmi3 (mentor) swills (mentor)
Differential Revision: https://reviews.freebsd.org/D8337