Docker daemon always stops healthcheck before sending signal to a
container now. However, when we use "docker kill" to send signals
other than SIGTERM or SIGKILL to a container, such as SIGINT,
daemon still stops container health check though container process
handles the signal normally and continues to work.
Signed-off-by: Ruilin Li <liruilin4@huawei.com>
(cherry picked from commit da574f9343)
Signed-off-by: Dani Louca <dani.louca@docker.com>