5210f3b532
this commit makes the ldap realm endpoints check whether a new or updated configuration works correctly. it uses the new `check_connection` function to make sure that a configuration can be successfully used to connect to and query an ldap directory. doing so allows us to remove the ldap domain regex. instead of relying on a regex to make sure that a given distinguished name (dn) could be correct, we simply let the ldap directory tell us whether it accepts it. this should also aid with usability as a dn that looks correct could still be invalid. this also implicitly removes unauthenticated binds, since the new `check_connection` function does not support those. it will simply bail out of the check if a `bind_dn` but no password is configured. therefore, this is a breaking change. Signed-off-by: Stefan Sterz <s.sterz@proxmox.com>