Set sles_auth_token in yum-repository form for synching SLES-repos from SCC
To sync SLES Repositories from Suse Customer Center an additional authentication-token needs to be added to the repository URL.
With pulp2 it was enough to add `?<TOKEN>` to the end of the repository-url.
Pulp3-RPM requires to supply the token as a separate parameter when creating the Remote: https://pulp-rpm.readthedocs.io/en/latest/workflows/create_sync_publish.html#configuration-for-sles-12-repository-with-authentication
This error occurs when using foreman_scc_manager plugin: https://github.com/ATIX-AG/foreman_scc_manager/issues/43