Encourage users to verify that obsolete repositories have been removed

[rloutrel]

A lot of users of the owncloud repository (but certainly relevant for all of the projects which have migrated to the opensuse solution) are using the documentation from the new repository when their configuration is still referencing the old repository.

I only know debian-like world (and the /etc/apt/source.list.d/xxx files) but I assume, that the same problem may impact other distributions.

The advice could just be a "check your files" or a script (here for ubuntu) equivalent to:

repoId=owncloud
grep -ri $repoId /etc/apt/sources.list /etc/apt/sources.list.d/*.list

should returns only one result