Asterisk 16.0.1 update

[Rob Thomas]

As Asterisk 16 is the current Stable/LTS release, I've updated the
code from your repo and placed it here:

https://github.com/phonebocx/asterisk

The only thing that jumps out at me as potentially being an issue is
that you're re-enabling chan_vpb, which is not only deprecated, it
probably won't work at all (not to mention you can't buy the hardware
that this is for, AND they've got their own 'supported' PBX now).

I've done it as two major commits. The first one is a single upgrade
to 16.0.1, and the second is simply upgrading the patches to suit.

https://github.com/phonebocx/asterisk/commit/d707c95bd2a2c6f6866a23fc8dec201556b380f4

https://github.com/phonebocx/asterisk/commit/4c968220cd82e8b0c651c694d8c26ee38a3e99ec

The third is to fix building in sbuild, as it doesn't have curl and
ca-certificates by default (or, it didn't in mine), so I've added them
to Build Requires.

https://github.com/phonebocx/asterisk/commit/78742a56a146fa0b79bd9f0e4ed83e05ffb79153

There will probably be OTHER commits, after I finish testing this
build but those are the only three that are relevant here.

Hope this helps!

--Rob