Corrected gpgkey for RHEL EE

[bFekete]

Closes #194

[LongLiveCHIEF]

There isn't an ee key or a ce key. they all redirect to a single key. The current url isn't a typo, it's just inconsistent.

In a future PR I'll be simplifying the package management, and the whole key designation stuff between packages will be removed entirely, For this reason, I'd rather leave this as is at the moment, just to prevent the misconception that keys are uniquely distinct for gitlab editions.