Fixed quic_method lookup in TLS 1.3 server side handshake.

Commit 3cbb0299a allows for quic_method to be configured
per-connection. However, before this, do_send_new_session_ticket()
in ssl/tls13_server.cc read quic_method from the underlying
SSL context.

Change-Id: I04ea2be23dc8e32b3232b8f59e266bd381e8f3c4
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/38004
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
diff --git a/ssl/tls13_server.cc b/ssl/tls13_server.cc
index a52a49c..f6a81d4 100644
--- a/ssl/tls13_server.cc
+++ b/ssl/tls13_server.cc
@@ -976,7 +976,7 @@
   // the case of a small server write buffer. Consumers which don't write data
   // to the client will need to do a zero-byte write if they wish to flush the
   // tickets.
-  if (hs->ssl->ctx->quic_method != nullptr && sent_tickets) {
+  if (hs->ssl->quic_method != nullptr && sent_tickets) {
     return ssl_hs_flush;
   }
   return ssl_hs_ok;