make reauth test compat with tailscale head

[kradalby]

tailscale/tailscale@1eaad7d broke our reauth test as it makes the client retry with https/443 if it reconnects within 2 minutes.

This commit fixes this by running the test as a two part,

• with https, to confirm instant reconnect works
• with http, and a 3 min wait, to check that it work without.

The change is not a general consern as headscale in prod is ran with https.

Updates #2164