Thank you!

It looks like default MMS subject depends on mobile operator, because
subject is different in MMS sent from the same Android device.
For example, Beeline sets 'New MMS' as a default subject instead of
'NoSubject.

There's a REALLY annoying bug in 1.17, so enforce using 1.18.1 and later

c-ares only uses the DNS servers from modem manager now, so
let's default to it

This patch makes use of the broadband provider DNS servers provided by
ModemManager to resolve the IP of mmsc. This allows users to use
whatever DNS servers they want on their system, without needing to use
the broadband provider for MMS to work.

Also add Tim to list of contributors Thank you for your contribution!

g_hash_table_destroy() clears the memory automatically, so no need to
do that.