PutReviewers: Only validate reviewer input when adding

If the reviewers.config contains a reviewer name that is invalid, i.e.
does not match an existing account or group, trying to remove that
reviewer via the UI results in an error.

Only validate the input when a reviewer is added.

Change-Id: I4677bca99cf0ab476fe5a5dcd106b98cfd08b9dc
1 file changed
tree: 93c65fed09415c6f1bb932a9f40642a9733c3989
  1. .buckconfig
  2. .gitignore
  3. BUCK
  5. lib/
  6. pom.xml
  7. src/
  8. tools/