Merge branch 'js/early-config-with-onbranch'

The recently added [includeif "onbranch:branch"] feature does not
work well with an early config mechanism, as it attempts to find
out what branch we are on before we even haven't located the git
repository.  The inclusion during early config scan is ignored to
work around this issue.

* js/early-config-with-onbranch:
  config: work around bug with includeif:onbranch and early config