langselector: modify env 'LANGUAGE' value

Change-Id: Ic458d893512c6faf2d55b3a220b12c3ee8167163
tower: https://tower.im/projects/8f19f0bf0e754f0b82ef2c24bc230973/todos/52d93851a0da4a6e8bab57e8cb8c153c/