valid ldap auth_source item _has_ to be id 1
After adding a new LDAP server to log on to, I couldn't delete the old LDAP server, so I removed the DB row in auth_sources. This didn't work, so I restored the old entry, which also didn't work. Then it struck me, the only difference was the rows `id`. Changing that did re-enable authentication. After that I saw the light, I added the new LDAP server and used the following commands to change the row id for the old LDAP server to 3 and the new LDAP entry to 1:
update auth_sources set id = '3' where id = '1'; update auth_sources set id = '1' where id = '2';
And only after that I could delete the original LDAP server in the web-interface and everything works as hoped for.
This should of course not be necessary.