Addressbook: Notify views after locale change

After changing locale, views of EBookBackend are not notified about
modifications made during that operation. Changing locale of
EBookBackend may result in updating EVC_X_E164 parameter of phone
numbers as its value depends on currently used locale. Calling
e_book_backend_notify_complete after successfully changing locale
notifies views about possible modifications.

Cherry picked from commit in master:
Bug 732730 - Addressbook: Notify views after locale change 0513c56

Fixes BGO: 732730