Input "Z" and "T" in the To: field, show all contact with phone number, even the contact name doesn't include "Z" and "T"

[Hannah Zhu]

Information:
current build number: 402
device name: krillin
channel: ubuntu-touch/rc-proposed/bq-aquaris.en
last update: 2016-08-08 09:35:04
version version: 402
version ubuntu: 20160806
version device: 20160606-ab415b2
version custom: 20160701-981-38-14

Precondition:
Address book contains some contacts with phone number (contact name can be blank or doesn't include "Z" and "T" character)

Step:
1. Open message app, input "Z" and "T" character in the To: field

Actual result:
It show all contact with phone number,even the contact name doesn't include "Z" and "T" character.

Expect result:
Should show the relative contact.