Check if we are treating incoming group member name as full OCM users

[michielbdejong]

E.g. jan@harderwijk.com Or jan@gmail.com@harderwijk.com

[T0mWz]

So we send to both always the same federated userid oc1.docker.com pietje@example.com@oc1.docker.com klaas@example.de@oc2.docker.com oc2.docker.com pietje@example.com@oc1.docker.com klaas@example.de@oc2.docker.com Then we can check on an instance, if federated domain is eagle, then it's a local user

[yasharpm]

1. user name without @ is always local
2. username with a single @ can be local user (where email is username) or a federated user. Here, ask local owncloud of it knows this user. If false, then federated user
3. username with double @ is always a federated

@T0mWz @michielbdejong I think we can follow this logic.

[michielbdejong]

We checked this and it's OK.