Remove the deprecated redis_health_check field (#3896)

Fixes envoyproxy/envoy#3713

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>

Mirrored from https://github.com/envoyproxy/envoy @ b202f894fd24c96309e71657c9a033a08bd99415

envoy/api/v2/core/health_check.proto

@@ -152,16 +152,17 @@ message HealthCheck {
     // TCP health check.
     TcpHealthCheck tcp_health_check = 9;
 
-    // Redis health check.
-    RedisHealthCheck redis_health_check = 10;
-
     // gRPC health check.
     GrpcHealthCheck grpc_health_check = 11;
 
     // Custom health check.
     CustomHealthCheck custom_health_check = 13;
   }
 
+  reserved 10; // redis_health_check is deprecated by :ref:`custom_health_check
+               // <envoy_api_field_core.HealthCheck.custom_health_check>`
+  reserved "redis_health_check";
+
   // The "no traffic interval" is a special health check interval that is used when a cluster has
   // never had traffic routed to it. This lower interval allows cluster information to be kept up to
   // date, without sending a potentially large amount of active health checking traffic for no