Removing myself from OpenSER maintainers

[Peter Lemenkov]

Hello All!

I should have done this months ago - I'm removing myself from the
OpenSER maintainers. The upstream is dead for a very long time, and
everyone who's still using OpenSER must migrate to OpenSIPS (available
in Fedora/EPEL) or Kamailio (n/a in Fedora/EPEL).

Just for your info - I'll continue co-maintaining OpenSIPS in the
foreseeable future.
-- 
With best regards, Peter Lemenkov.