misc: fix qml warnings

1. When there is no contact, some properties in smart list view could be null
2. When creating new accounts from no accounts, adding a new contact and
   switch accounts will cause "Contact out of range". This is caused by
   smartlist model account id does not update at that time. Instead,
   use current account id always.

Change-Id: Ic42ec33c4932908caff2ebca2814903f95c12a10