Bug 1023764 - [Loop] Keep Contacts Info updated. r=borjasalguero, jaoo

Being here you have done the effort of retrieving the Contact, so why dont we pass it as a param and we delegate in the `_updateListWithContactInfo` for doing the logic of the identities? Furthermore, within `_updateListWithContactInfo` we are calling `_updateContact` which is requesting again for a Contact given an ID, so we are making the effort twice.