fix: docker/images/n8n-ubuntu/Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-DEBIAN9-OPENSSL-1569399
- https://snyk.io/vuln/SNYK-DEBIAN9-PYTHON35-1013421
- https://snyk.io/vuln/SNYK-DEBIAN9-PYTHON35-1063181
- https://snyk.io/vuln/SNYK-DEBIAN9-PYTHON35-584364
- https://snyk.io/vuln/SNYK-DEBIAN9-SUBVERSION-1071813

docker/images/n8n-ubuntu/Dockerfile

@@ -1,4 +1,4 @@
-FROM node:12.19
+FROM node:12.22.6
 
 ARG N8N_VERSION