Fix broken rid

[m7x]

Current setup is broken. The victim's click gets recorded in gophish only if the user id rid parameter is chosen. This PR fixes this issue.

Also in the examples, there is user_id which is heavily used in the code. A simple find / replace of that string will break the setup. It's better to suggest a very custom_user_id so it's unique enough to survive a find / replace of replace_rid.sh in the entire source code.