Steps to reproduce:

1. New Item
2. New GitHub organisation
3. Item Name 'hafner-hm-edu'
4. Repository Sources -> GitHub Organisation -> Scan Credentials -> Add
5. Select 'Hochschule ...'
6. [Popup] Select Kind 'ssh user name with key'
7. [Popup] Select 'From the Jenkins master ~/.ssh'
8. [Popup] Enter something in passphrase
9. [Popup] Press Add
10. [Popup closes without info or error
11. Scan Credentials listbox is still empty