shouldn't show searchtableview when there are no filtered contacts

[fans3210]

since 'filteredContacts' is private, user wouldn't know whether there are search results. There is always a tableview shown even when the filteredContacts count is 0.

[fans3210]

The contact picker should either show a searchtableview only if the num of filteredcontacts is not zero, or let user access the filteredcontacts property to let the user decide the ui change depends on the filteredcontacts