Stop contact editor from adding empty field if no more types.

If there was a field with 1 type and you entered in a value it
popped up a new field for the same kind.

i.e. Add a birth date for new exchange contact

Change-Id: I3a0567d8f4c031ad6bfb0772dac5d116547f6041
Ticket-Id: HAM-291
(cherry picked from commit 6c3c5890)