Update npm registry URL in docker-compose.yml (#292)

When the service was renamed, the config was not updated.

Author: hardillb

docker-compose.yml

@@ -42,7 +42,7 @@ configs:
         url: http://file-server:3001
       npmRegistry:
         enabled: true
-        url: http://npm:4873
+        url: http://npm-registry:4873
         admin:
           username: admin
           password: ${NPM_PASSWORD:-secret}
@@ -600,4 +600,4 @@ volumes:
   fileStorage:
   acme:
   emqx:
-  npm-registry:
+  npm-registry: