The agents update command fails with a useless message

[psanders]

Describe the bug
Using the fonoster agents:update command fails with a useless message.

To Reproduce
Steps to reproduce the behavior:

1. Go to your console
2. Create a new Agent or use an existing one
3. Then attempt to update using fonoster agents:update [ID]
4. See error

Error example:

Error: 9 FAILED_PRECONDITION: $[0].spec.credentials.username: must be at least 3 characters long, $[0].spec.credentials.username: is a readonly field, it cannot be changed

Expected behavior
There should be no errors

System information (please complete the following):

• OS: OSX
• NodeJS, NPM versions: v14.16.0, 7.10.0
• CTL version: 0.2.17

Additional context
No

[psanders]

Note for myself: The fonoster providers:update has a similar problem.