The original API that queries by label (`/rest/api/latest/result?label=#{sha1}`)
only works for results from main plans and not branch plans. The
`/rest/api/latest/result/byChangeset/#{sha1}` endpoint gives results from
branch plans but not for the first push to the branch. Subsequent pushes
work.

For more details, see https://jira.atlassian.com/browse/BAM-16121.

Closes #1355