Set kibana to log to fluentd

This would only be a problem if fluentd wasn't running, but
since fluentd doesn't log to fluentd, kibana wouldn't help anyway.

docker-compose.logging.dev.yml

@@ -14,5 +14,3 @@ services:
   kibana:
     ports:
       - "5601:5601"
-    logging:
-      driver: "fluentd"

docker-compose.logging.yml

@@ -35,6 +35,8 @@ services:
       driver: "json-file"
   kibana:
     image: kibana:7.9.0
+    logging:
+      driver: "fluentd"
     networks:
       - logging
     deploy: