Default branch on a repo is not respected in deep links to code

[evilstickman]

When a repo is configured with a default branch, that branch is correctly used when indexing content. However, deep links in the code ignore this setting and link to the file and line numbers in the master branch, which may or may not exist. To see this problem in action:

1 - Navigate to http://codesearcher.int.sproutsocial.com/search/?q=oauth_is_valid&case=sensitive#web-app-messaging_github
2 - Click the first link

Currently this is a link to https://github.com/sproutsocial/web-app-engagement/blob/master/application/controllers/support/start.php#L2503, which does not exist. The link should go to the repo's default branch, which is "engagement", and the link should be https://github.com/sproutsocial/web-app-engagement/blob/engagement/application/controllers/support/start.php#L2503