[openssl/openssl] dac42b: Fix a bad merge in quic-multi-stream.c demo

[Matt Caswell]

  Branch: refs/heads/master
  Home:   https://github.com/openssl/openssl
  Commit: dac42bdce1ed19e646c2adf04b27fc92a9d0e374
      https://github.com/openssl/openssl/commit/dac42bdce1ed19e646c2adf04b27fc92a9d0e374
  Author: Matt Caswell <matt at openssl.org>
  Date:   2023-08-28 (Mon, 28 Aug 2023)

  Changed paths:
    M demos/guide/quic-multi-stream.c

  Log Message:
  -----------
  Fix a bad merge in quic-multi-stream.c demo

The function SSL_set_initial_peer_addr() got renamed to
SSL_set1_initial_peer_addr(). The demo missed out on the rename when it
got rebased on top of it.

Reviewed-by: Hugo Landau <hlandau at openssl.org>
Reviewed-by: Tomas Mraz <tomas at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/21842)