Ban node using the wrong magic.

Summary:
A few host on the network keep using the wrong magic. They try to connect again and again to ABC nodes, which is undesirable. Because the node is disconected immediately, the banscore is not tracked accross connexion attempt and the node never gets banned. The long term solution may be to add a banscore per IP or subnet, but in the meantime, we can simply ban nodes using the wrong magic.

The host 23.92.36.9 on mainnet and 72.36.89.11 on testnet are especially bad offenders. Because of their suspicious behavior, they got added it to the suspicious host list.

Test Plan:
Run a node and monitor the logs. Make sure we now have many messages of the kind

connection from 23.92.36.9:23665 dropped (banned)

Instead of the usual INVALID MESSAGESTART error.

Reviewers: #bitcoin_abc, schancel

Reviewed By: #bitcoin_abc, schancel

Subscribers: teamcity

Differential Revision: https://reviews.bitcoinabc.org/D1234