reflect infrastructure move of bugs.python.org (to server bugs.ams1.psf.io)

[bernhardreiter]

At some time the infrastructure for bugs.python.org was moved to a different server.

It is very likely that it was moved off a server from Upfront Systems as still written in the overview, this would need to be corrected. The new server should be added to the list of server (and hopefully with ssh pubkey fingerprints as recommended by #104 :) )

details about the infrastructure move

See this comment: https://github.com/python/psf-infra-meta/issues/4#issuecomment-449401710

And a current ping shows that this is not psf.upfronthosting.co.za anymore:

date -u ; ping -c 1 bugs.python.org
                  
Mi 6. Mär 08:57:38 UTC 2019
PING bugs.python.org (188.166.48.69) 56(84) bytes of data.
64 bytes from bugs.ams1.psf.io (188.166.48.69): icmp_seq=1 ttl=56 time=16.7 ms