Update CONTRIBUTING.md

Author: curquiza

CONTRIBUTING.md

@@ -42,7 +42,7 @@ Each PR should pass the tests to be accepted.
 ```bash
 # Tests
 $ docker pull getmeili/meilisearch:latest # Fetch the latest version of MeiliSearch image from Docker Hub
-$ docker run -p 7700:7700 getmeili/meilisearch:latest ./meilisearch --master-key=masterKey --no-analytics
+$ docker run -p 7700:7700 getmeili/meilisearch:latest ./meilisearch --master-key=masterKey --no-analytics=true
 $ bundle exec rspec
 ```