net/freeswitch: Update to 1.6.19

[ultima]

Summary

• Updated to 1.6.19
• Modernized port
• Moved ONLY_FOR_ARCHS, Comes before *_DEPENDS and after LICENSE section
• Moved and sorted USES, and USE_x section
• Sorted Options section

PR\: 220149
Sumitted by\: Šimun Mikecin <[e-mail]>
Reviewed by\: lifanov (mentor), matthew (mentor)
Approved by\: lifanov (mentor), matthew (mentor), <[e-mail]> (maintainer, pending approval)
Differential Revision\: https://reviews.freebsd.org/DXXXXX

Test Plan

portlint:
WARN: Makefile: for new port, make $FreeBSD$ tag in comment section empty, to make SVN happy.
WARN: Makefile: use of DISTFILES with single file discouraged. distribution filename should be set by DISTNAME and EXTRACT_SUFX.
WARN: Makefile: "LIB_DEPENDS" has to appear earlier.
WARN: Makefile: DISTFILES/DISTNAME affects WRKSRC. take caution when changing them.
0 fatal errors and 4 warnings found.

false positives

poudriere:
103i386: is only for amd64, while you are running i386
103amd64
110i386: is only for amd64, while you are running i386
110amd64
12i386: is only for amd64, while you are running i386
12amd64

[matthew]