Update link to --secret option (#2562)

rabbitmq/content.md

@@ -88,7 +88,7 @@ For example, you can provide the cookie via a file (such as with [Docker Secrets
 docker service create ... --secret source=my-erlang-cookie,target=/var/lib/rabbitmq/.erlang.cookie ... %%IMAGE%%
 ```
 
-(Note that it will likely also be necessary to specify `uid=XXX,gid=XXX,mode=0600` in order for Erlang in the container to be able to read the cookie file properly. See [Docker's `--secret` documentation for more details](https://docs.docker.com/engine/reference/commandline/service_create/#create-a-service-with-secrets).)
+(Note that it will likely also be necessary to specify `uid=XXX,gid=XXX,mode=0600` in order for Erlang in the container to be able to read the cookie file properly. See [Docker's `--secret` documentation for more details](https://docs.docker.com/reference/cli/docker/service/create/#secret).)
 
 ### Management Plugin