Security review of web infrastructure

[m-kuhn]

• [x] Postgres server is not reachable from outside
• [x] Connection to webserver is over a securely encrypted https connection
• [x] The database user does not have the rights to modify the data structure (delete attributes)
• [x] sudo access disabled

[tlh22]

Guacamole now allows use to step validation. It would be good to implement this.