Some search users pages do not care about authenticator choice

[dmartinc]

In the search user page that appears for the "Log me in as" functionality, checking the "search Nice database" does not have any effect; the search is only limited to the local DB.

In the opposite way, the search user page that appears when adding a new Server Admin always searches Nice even if the checkbox is not checked.

In other pages it works properly, such as the add chairpersons page; we get different results depending if we checked the checkbox or not.

Gradually we should replace all these search user pages by the search user dialog.

[jbenito]

done