Adx 986 mail not sent when user requests to be an organisation admin

[A-Souhei]

Description

No email received by sysadmin when a user requests to be admin of an organisation. Fixed on local, also added a regression test.

Checklist

Put an x in the boxes that apply to this pull request (you can also fill these out after opening the pull request).
You may not need to check all boxes.

• The Jira ticket for this issue has been updated to "Ready to Review" or equivalent.
• I have developed these changes in discussion with the appropriate project manager.
• My code follows the general Fjelltopp documentation (see Confluence).
• I have made corresponding changes to the Fjelltopp documentation (see Confluence).
• I have rebased this branch with master.
• New dependency changes have been committed.
• I have added automated tests that prove my fix is effective or that my feature works.
• New and existing tests pass locally with my changes.
• My changes generate no new warnings.
• I have performed a self-review of my own code.
• I have assigned at least one reviewer.