#3 Change the way we detect "invalid" / "banned" usernames

Go from reading the "msg" field to "username" field...

This way we can block names like:

• root (which currently is the only one blocked)
• postgres
• etc...

Should be as simple as

if j["username"] in bad_users:
    # they are a bad user, block them!

[9a9d5921c9] fixes this so we can just add it to the JSON then restart the script.

But... if it's miss spelled then we won't detect it.