FreeSWITCH

Fix docs on enabling cert CN/SAN validation

The correct incantations to enable certification common name / subject
alternative name verification, per our code, are `subjects_all`,
`subjects_in`, and `subjects_out` in a Sofia profile's
`tls-verify-policy`.  What we've had in our examples and documentation
for years are `all_subjects`, `in_subjects`, and `out_subjects`.

The result of this is that we've almost certainly confused people into
using the incorrect forms.  Those poor people will believe that they
are verifying the CN/SAN of the received host certificate against the
list in `tls-verify-in-subjects` when in fact they are not.

One clear issue in this case was that the incorrect forms failed to
have any effect without providing any warning or error.  This issue
could not have persisted if we had made more noise about incorrect
input.

Given how long this has been broken, it's tempting to alias the
incorrect forms to the correct ones.  However this would certainly
break many existing installations that have, because of this error,
never actually tested their setup with CN/SAN validation enabled.

In this commit, we fix the examples and documentation, and add an
error-level log output when unknown values are passed to
`tls-verify-policy`.

Thanks-to: Andrew Patrikalakis <anrp+freeswitch@anrp.net>