Fix language of insatall in auto mode

1. change the LANG & LANGUAGE
2. set insatll log path to deepin-installer

tower: https://tower.im/projects/8f19f0bf0e754f0b82ef2c24bc230973/todos/610720559e4b48adb36e817c3d2bde49/

Change-Id: If8ef7c1ada00ed79d06925f4c634a707b6beef10