Initial load fails for new Git Gateway instance

**Describe the bug**

When initially logging in to a new Git Gateway site, login fails and a yellow toast notification says the Git Gateway instance is not setup, or something like that. Reloading allows login to proceed.

**To Reproduce**

1. Use Deploy To Netlify to deploy a site with Git Gateway enabled: https://app.netlify.com/start/deploy?repository=https://github.com/andybelldesign/hylia&stack=cms
2. Accept the CMS invite via invite email
3. Go to /admin on the new site

**Expected behavior**

Login should work the first time.

**Screenshots**

**Applicable Versions:**

All. This has been going on forever.
**CMS configuration**

Unrelated.

**Suggested solutions**

There must be some difference in the initial settings retrieved from Git Gateway - we probably need to find out what that difference is, and refetch when it happens.