chore: make healthcheck output concise

Author: 7-zete-7

Dockerfile

@@ -48,7 +48,7 @@ COPY --link frankenphp/Caddyfile /etc/frankenphp/Caddyfile
 
 ENTRYPOINT ["docker-entrypoint"]
 
-HEALTHCHECK --start-period=60s CMD curl -f http://localhost:2019/metrics || exit 1
+HEALTHCHECK --start-period=60s CMD curl http://localhost:2019/metrics --silent --show-error --fail --output /dev/null || exit 1
 CMD [ "frankenphp", "run", "--config", "/etc/frankenphp/Caddyfile" ]
 
 # Dev FrankenPHP image