Fix a use-after-free in quic_tls.c

Fix a use-after-free in quic_tls.c

The comments in quic_tls.c claimed that the dummybio was never used by
us. In fact that is not entirely correct since we set and cleared the
retry flags on it. This means that we have to manage it properly, and update
it in the event of set1_bio() call on the record layer method.

Reviewed-by: Hugo Landau <hlandau@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/21686)