"Test Configuration" button seems broken?

[ragaskar]

Describe the bug
The "Add Repo" form has a "Test Configuration" button that appears to return the error guid is required regardless of settings. However, this validation appears to be erroneous, as clicking "Submit" allows the repo to be created, and as far as I can tell, the repo seems to be working correctly? (I am a new backrest/restic user, so ... not really sure the best way to validate correct operation, but this seems like a big showstopper and I could not find an existing bug for it. I felt lucky to find a reddit thread where someone experienced this issue and another redditor replied "yeah just submit anyways", otherwise I would have never thought to just submit the form).

To Reproduce

1. Go to 'Add Repo'
2. Fill out details -- in this case I am using the S3-compatible API for Backblaze B2.
3. Click the "Test Configuration" button
4. An error modal appears, with the message

* guid "" invalid: must be 64 characters
* guid is required

5. There are no "guid" fields on the form to fill out, from what I can tell (it feels like there's probably a guid being stored with a repo -- maybe just on the backrest side? -- but in the case of a new repo that guid doesn't exist yet?)

Expected behavior
The repo validation form should only return validation errors for values that are actually invalid and are correctable by the user.

Platform Info

• OSX LibreWolf
• backrest version 1.7.0@6d4b56f9e3ed6535ee654fea1af2bec8d4f984b2

Additional context
Thanks for backrest, looks super cool! I did get a bit stuck here, since I thought I might have put in an incorrect URI, since there's no docs with good examples of what a backblaze b2 s3-compatible URI should look like (s3-compatible since the docs say to use that instead of b2 w/ backblaze, because it sounds like the b2 lib spams debug errors to the logs). But .. it looks like it worked! (for those trying to figure it out, you'd grab your "Endpoint" for the bucket you created from the Bucket Settings page, and then you add your bucket name -- so, something like: s3:s3.us-west-001.backblazeb2.com/your-bucket-name. No scheme! (that is, no s3:// or https://).