The annoyance is similar to that of "Sourcetree asking for password again and again" except that in my case, I don't use the repository anymore and I don't want to solve the password storage problem, so the answer I am looking for is different.
I think I removed all references to the repo in SourceTree but it still appear in the Options/Authentification tab. There, there is an "Add" label, but no "Delete".
