Fixup rt.perl.org/rt3 => rt.perl.org

These links all would redirect properly, but give out the top URL.
Allow newer bug URLs on rt.perl.org
update RTSERVER

This didn't work properly as is (because of the redirect from
http://rt.perl.org/rt3/ to https://rt.perl.org/rt3/) but at least it'll
work if someone tries it going forward.
No longer point to rt.perl.org/perlbug/ as a landing page

We'll use the homepage of rt.perl.org instead, as it's much more likely
to get text updates.
Add Kevin Falcone to AUTHORS
Regen META.{yml,json}

(If t/porting/regen.t fails without this regeneration, why doesn’t
‘make regen’ do this?)