would rearchive users which had been unarchive in the first place
on the way:
* use sets to remove duplicates
* don't query all ldap configurations if one has said the user must be archived
* improve the view by not relying on a string attribute
* [ADD] possibility to deactivate users not found in ldap while populating
* [IMP] search in ldap for every possibly unknown user to be really sure it
actually is not present there
* [FIX] refactoring mistake
* [IMP] don't use self.query() to be sure to be stopped if any error occurs
* [IMP] remove superfluous check as exceptions are not supressed any more
* [FIX] typo in variable name
[FIX] handle unicode characters in search filter
[FIX] search for user's login, not her name
* [FIX] don't pass user_name as assertion_value
* [FIX] don't deactivate users if we got a non-existent ldap configuration
* [FIX] flake8
* [FIX] more flake8
* [FIX] make form usable
* [FIX] name clash between function and field
* [ADD] test