Sync of content from an authenticated yum repository fails
Steps to Reproduce:
1. try to sync an image from an authenticated yum repository with username and password
the sync task ends in a warning state. With an error along
`NoMethodError: undefined method `username' for #<PulpRpmClient::RpmRpmRemoteResponse:0x000000002c4ee1f8>
The community link has a lot more details on this.