sysutils/py-mqttwarn: update to 0.13.8

[dvl]

Summary

Update to 0.13.8

Test Plan

This is incomplete. I started the process of upgrading. There is
a Makefile with the vendor code. It is gmake but I was not able to make that
work either. I think the issue is my lack of Python 3 knowledge. I'm
creating this review to share with the vendor author who is gaining some
FreeBSD porting experience.

[dvl]

sysutils/py-mqttwarn/Makefile

40

${WRKSRC}/mqttwarn is a directory, not the main executable. This is not the correct thing to install to sbin

sysutils/py-mqttwarn/files/patch-mqttwarn_examples_basic_mqttwarn.ini

7

This patch needs to be Python-version independent.

[dvl]

Let's use a newer version of the vendor code.