don't send 1-RTT packets before the handshake is complete
don't send 1-RTT packets before the handshake is complete

We shouldn't send 1-RTT packets before the handshake is completed (i.e.
before receiving the Finished message) as per RFC8446, section 4.4.4.

This is already enforced a few lines later for normal packets, but the
error and probe cases were missed.

cloudflare/quiche,cloudflare/quiche,cloudflare/quiche