Context

Rejections will send messages, since we only store message hashes. We need to check that these hashes are correct.

Manually testing the MR

There are presently no tests for this, since we don't have real rejections yet. When we test real rejections, we will add a test that runs this code.

Document the interface of any function added or modified (see the coding guidelines)
Document any change to the user interface, including configuration parameters (see node configuration)
Provide automatic testing (see the testing guide).
For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
Select suitable reviewers using the Reviewers field below.
Select as Assignee the next person who should take action on that MR