docker: hide healthcheck from logs

docs/examples/docker/basic-docker-compose/docker-compose.yml

@@ -17,7 +17,8 @@ services:
 
     stop_grace_period: 15s  # thumbnailer is allowed to continue finishing up for 10s after the shutdown signal
     healthcheck:
-      test: ["CMD-SHELL", "wget --spider -q 127.0.0.1:3923/?reset"]
+      # hide it from logs with "/._" so it matches the default --lf-url filter 
+      test: ["CMD-SHELL", "wget --spider -q 127.0.0.1:3923/?reset=/._"]
       interval: 1m
       timeout: 2s
       retries: 5