Switch over main server to other domain

[UsualSpec]

Currently we still use the non memorable domain in the configs. This should be changed in the next deployment.

[UsualSpec]

• Change CN in Let's encrypt certs
• Resign CA on the server with new domain
• Switch default config to use new domain

[UsualSpec]

This could be done, but I'd prefer not to touch this until we have no devices deployed anymore.
In this case, every certificate needs resigning, every instance pointing to the old domain needs to be changed to a***.*.ch (go over all config files).

Then, we'd re-test that every device can register.