🐛 Add mailcatch to penpot network on docker compose

Without this the backend complains that it cannot connect to the smtp host (when using mailcatcher). The reason is because the mailcatcher is not on the same network as the backend application.

docker/images/docker-compose.yaml

@@ -259,6 +259,8 @@ services:
       - '1025'
     ports:
       - "1080:1080"
+    networks:
+      - penpot
 
   ## Example configuration of MiniIO (S3 compatible object storage service); If you don't
   ## have preference, then just use filesystem, this is here just for the completeness.