HealthCheck: add validation for minimum accepted start-interval

This is a follow-up to 2216d3ca8d, which
implemented the StartInterval for health-checks, but did not add validation
for the minimum accepted interval;

> The time to wait between checks in nanoseconds during the start period.
> It should be 0 or at least 1000000 (1 ms). 0 means inherit.

This patch adds validation for the minimum accepted interval (1ms).

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

daemon/container.go

@@ -333,6 +333,9 @@ func validateHealthCheck(healthConfig *containertypes.HealthConfig) error {
 	if healthConfig.StartPeriod != 0 && healthConfig.StartPeriod < containertypes.MinimumDuration {
 		return errors.Errorf("StartPeriod in Healthcheck cannot be less than %s", containertypes.MinimumDuration)
 	}
+	if healthConfig.StartInterval != 0 && healthConfig.StartInterval < containertypes.MinimumDuration {
+		return errors.Errorf("StartInterval in Healthcheck cannot be less than %s", containertypes.MinimumDuration)
+	}
 	return nil
 }