offliner manifest references RH artifacts using wrong versions

The offline repository generator is unable to download many artifacts that are listed in the manifest file for 7.3.1.

There mainly seem to be two types of problems:

• manifest file references RH versions that do not exist because the versions referenced miss the -redhat-0000x appendix
• manifest file references external artifacts that cannot be resolved.

I attach an errors.log that should already be cleared of any incorrect entries (like path names) for further investigations