fix english expression and update pot

tower: https://tower.im/projects/8f19f0bf0e754f0b82ef2c24bc230973/todos/0b4cee1358bb46788ee8db41adced801/
tower: https://tower.im/projects/8f19f0bf0e754f0b82ef2c24bc230973/todos/0cb951d8d6d4470da869b653ede88c5b/

Change-Id: Ied3895b7bf6f653d715d7da7cbf8ec271615b9b5