Automatic plan branches don't send emails on first build

Configure a plan with automatic plan branching that runs a shell script and checks for non-zero exit status.

Create a branch and modify the shell script to fail (breaking the build). Push the branch. Bamboo will automatically create a plan branch for the branch and it will fail.

Expected: Send an email to the committer notifying them of the failure.

Actual: Bamboo says that the plan branch has "no changes" because this is the first build of the plan branch, so there are no committers, so nobody gets an email.

This is particularly bad for short-lived Gatekeeper bug branches, where there's intended to be only one commit on the branch before Gatekeeper builds it and merges it into master. These Gatekeeper builds send no emails at all.