[Photon] New photon demo server and URL

[Sarah Hoffmann]

Hi,

last week we have moved the Photon demo service to a more powerful
server and also have upgraded the software to the latest version.

As part of this switch, the service has also moved to a new location:

  https://photon.komoot.io

Please update your scripts and libraries. There are redirects in
place for the old URLs but there have been reports that CORS is not
always playing nicely with the redirects.

In other news: we have now Photon database dumps for countries. Read
https://nominatim.org/2020/10/21/photon-country-extracts.html
for details.

Kind regards

Sarah