Bug 963043 - Message recipient from call log

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Since the result could be array, please update the unit test because it only verify callback with object. Please see https://github.com/mozilla-b2g/gaia/blob/master/apps/sms/test/unit/thread_ui_test.js#L4664 and add another test that callback with contact array. For example, returning an array with 2 contact objects and verify sinon.assert.calledTwice(ThreadUI.recipients.add)... something like that