Change reserved words for repository names

In previous versions, creating new repository names starting with 'artifactory-' or 'jfrog-' is blocked.
Already existing repositories will continue to function properly, but this blocks the creation of additional repositories following the same naming convention, which is a problem in cases where repository creation is automated through self service, changing the automation, and renaming all existing repos is a big effort with no obvious benefit for the user.
Users with such setups are now unable to upgrade Artifactory without making this effort.