Move bridge to a permanent faster server

Background: [tor-project] More resources required for Snowflake bridge

I expect to be able to move the snowflake bridge to a more permanent home on a faster server after 2022-03-21.

#40110 (closed) is to use a different faster server in the meantime, until the permanent one is prepared.

• get access to new server hardware
• install new bridge (installation guide)
• copy user accounts #40091 (comment 2768855)
• copy identity and onion keys from existing bridge
  • double check onion keys

    # md5sum /var/lib/tor-instances/*/keys/secret_onion_key{,_ntor}
    f57a05262f65beea15ec05bbeefe404c  /var/lib/tor-instances/snowflake1/keys/secret_onion_key
    a16c5403d18509c79fa7b863eb66892a  /var/lib/tor-instances/snowflake1/keys/secret_onion_key_ntor

• copy HTTPS TLS keys and certificates from existing bridge
• test tor bootstrap on new bridge using local broker and proxy, and /etc/hosts domain name record #40095 (comment 2773365)
• test rebooting the server to make sure everything comes back up
• start the tor@snowflake* services
• make DNS for snowflake.torproject.net point to the new bridge tpo/tpa/team#40716 (closed)
• monitor for a day, be ready to switch DNS back if connections fail
• after a week or so, shut down temporary bridge

Cc @linus