Ignore port for trusted domains

This lead to a lot of confusion in the past and did not really offer any value. Let's remove the port check therefore. (it's anyways not really a part of the domain)

Fixes https://github.com/owncloud/core/issues/12150 and https://github.com/owncloud/core/issues/12123 and also a problem reported by @DeepDiver1975.
Add repair steps for legacy config files

Remove all ports from the trusted domains
add newline
Merge pull request #12154 from owncloud/ignore-port-for-trusted-domain

Ignore port for trusted domains