Add a GPG Key Error Messages
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### Proposal
Customer is requesting a change to the GPG Key error handling.
**1. Current error message displayed when using a GPG Key that is too long:**
- Fingerprint has already been taken
- Primary keyid has already been taken
Proposed error message if the key is invalid or too long:
The form contains the following errors:
- The GPG key you've uploaded is invalid or too long.
- (Add a link for how to check for and print an existing GPG key on your computer)
**2. Current error message currently displayed if GPG Key is too short:**
The form contains the following errors:
- Fingerprint can't be blank
- Primary keyid can't be blank
Proposed error message if the key is too short:
- The GPG key you've uploaded is invalid or too short.
- (Add a link for how to check for and print an existing GPG key on your computer)
[Related customer ticket.](https://gitlab.zendesk.com/agent/tickets/490241) (You need access to internal tickets)
issue