Unknown Error when cloning the git repo

When setting up the app for the first time, the app gets stuck on the "Cloning ..." screen. I'm using a self-hosted gitolite repo and a non-standard port. In the logs, after a minute and a half or so I can see the following :

```
11-24 22:43:20.688 14750 14750 I GitJournalAndroid: Called method gitFetch
11-24 22:43:20.688 14750 14750 I GitJournalAndroid: . folderPath: /data/user/0/io.gitjournal.gitjournal/app_flutter/journal
11-24 22:43:20.688 14750 14750 I GitJournalAndroid: . privateKey:
11-24 22:43:20.688 14750 14750 I GitJournalAndroid: . password:
11-24 22:43:20.688 14750 14750 I GitJournalAndroid: . publicKey:
11-24 22:43:20.688 14750 14750 I GitJournalAndroid: . remote: origin
11-24 22:43:20.688 14750 14750 I GitJournalAndroid: . statusFile: /data/user/0/io.gitjournal.gitjournal/code_cache/gj
11-24 22:45:02.098 14750 21954 E GitJournalLib: Url: ssh://git@git.example.com:54321/light/gitjournal
11-24 22:45:02.417 14750 21954 E GitJournalLib: gj_error_info: -3
11-24 22:45:02.417 14750 21954 E GitJournalLib: Error -3/1000: Unknown Error
11-24 22:45:02.417 14750 21954 I GitJournalAndroid: GitDefaultBranchTask: Unknown Error
11-24 22:45:02.420 14750 22353 E GitJournalLib: Public Key Path: /data/user/0/io.gitjournal.gitjournal/app_flutter/journal/.git/id_ed25519.pub
11-24 22:45:02.420 14750 22353 E GitJournalLib: Private Key Path: /data/user/0/io.gitjournal.gitjournal/app_flutter/journal/.git/id_ed25519
```