Cron Schedule not recognizing changes to Pull Request settings

## Problem Description
After disabling/enabling allow merge commits or allow rebase merging, the settings do not change automatically, even if there is a change compared to the actual configuration.
However, when changing another field, the change is recognized and the cron job also changes the Pull Request settings.

### What is actually happening
Changes to Pull Request settings are not recognized as changes.

### What is the expected behavior
When changing pull request changes, in the next cron schedule, the settings should be seen as changed.

## Context

### Are you using the hosted instance of probot/settings or running your own?
Running our own

### If running your own instance, are you using it with github.com or GitHub Enterprise?
github.com

#### Version of probot/settings
2.0.23-rc.11