When user try to restart a restarting container, docker client report
error: "container is already active", and container will be stopped
instead be restarted which is seriously wrong.
What's more critical is that when user try to start this container
again, it will always fail.
This error can also be reproduced with a `docker stop`+`docker start`.
And this commit will fix the bug.
Signed-off-by: Zhang Wei <zhangwei555@huawei.com>