Automatic tests

In order to ensure stability in the future, we should write automated tests for this module.

This is the plan issue that contains child issues for each described scenario that we want to test.

The early we write tests to module, the better it'll be.

This issue can be considered fixed when following child issues has been fixed:

• #2817175: Test: Someone with insufficient permissions tries to access configuration form
• #2817177: Test: Help texts should appear
• #2817181: Test: Error logging