Issue Summary

Branch plan create through a pull request is not disabled when the PR is deleted.

Steps to Reproduce

1. Create a plan, with the branch configuration set to "When pull request is created"
2. Create a repository in Bitbucket server. Link this repository to the plan.
3. In Bitbucket, create a branch and then a PR. A plan branch will be created in Bamboo.
4. In Bitbucket, delete the PR.

Expected Results

Just like when a branch is deleted, we expect the plan branch to be disabled immediately.

Actual Results

The plan branch remains enabled.

Workaround

The plan branch needs to be disabled or deleted manually.