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 when executing some of his test scripts.

@karlitschek This is against stable7. Please confirm. I think this makes sense to have it there as due to a trusted domain behaviour change (it now also verifies the remote.php traffic) some custom scripts may be broken.
That will work fine because of L43. Also take a look at the unit tests :-)