Use the correct field

The field check is used to enable/disable check in StackLight. The
correct name for the field that is setting HAProxy check is
health_check.
diff --git a/haproxy/proxy/listen/stacklight/redis.yml b/haproxy/proxy/listen/stacklight/redis.yml
index bd36cb4..881e8ed 100644
--- a/haproxy/proxy/listen/stacklight/redis.yml
+++ b/haproxy/proxy/listen/stacklight/redis.yml
@@ -4,7 +4,8 @@
       listen:
         redis:
           mode: tcp
-          check:
+          check: False
+          health-check:
             tcp:
               options:
                 - send PING\r\n