Hackbot is failing to submit a patch because of the commit message content

Example https://hackbot.moz.tools/runs/e6a23751-69dc-4a60-a60a-6d18ea717cae
```
Conduit error ERR-CONDUIT-CORE: Validation errors: - The value you have entered in "Summary" can not be parsed unambiguously when rendered in a commit message. Edit the message so that keywords like "Summary:" and "Test Plan:" do not appear at the beginning of lines. Parsed keys: testPlan.
```