Typically we landed this change on the day of the beta... at which point we bump the release in the version.php from dev to beta and change the maturity. As such the previous check fails and we stop lookin gat master, and instead look at MOODLE_30_STABLE... which doesn't exist yet.

Either need to:

1. Check for the branch remotely and fall back to master if it does not exist
2. Switch to checking the $maturity setting, instead of grepping fo 'dev' in $release
3. Both of the above