Add handling of corrupted SCM password data

Review Request #10393 — Created Jan. 26, 2019 and updated — Latest diff uploaded

Information

Review Board
release-3.0.x
46ef38e...

Reviewers

E.g. after a database import the SCM repository passwords can no longer
be decrypted. This would lead to an exception when trying to decode the
password to UTF-8. Instead, `Repository._get_password()` will now return
`None` resulting in requiring the user to reset the password.
  • Added SVN repository with authentication.
  • Dumped database using: mysqldump --all-databases
  • Imported the dump into a fresh MySQL instance.
  • Successfully navigated to: /admin/db/scmtools/repository/1/
  • Observed error message in log.