CheckSkippedRepositories: improve the remediation instruction

[pirat89]

The current remediation instruction tells people to open support ticket when discovered a repository which contains RH signed RPMs. However, it could be that people could create own repositories with our packages (with different name). In such case the msg could be misleading. It could be better to mention a condition, that they can open support ticket in case it is repository provided by RH (with the original name), otherwise we will not support it - in those cases, they should change the repository name (it this helps - not sure whether repo name is changed in the record about installed rpm from yum, as we are getting it).