main/opensmtpd: use openssl 1.1

openssl 3.0 breaks tls:
$ smtpd -dV -Tall
...
debug: SSL library error: io_dispatch_accept_tls:SSL_accept: error:020000B3:rsa routines::missing private key
debug: SSL library error: io_dispatch_accept_tls:SSL_accept: error:1C880004:Provider routines::RSA lib
debug: SSL library error: io_dispatch_accept_tls:SSL_accept: error:0A080006:SSL routines::EVP lib
smtp: 0x7f5278fff010: IO_ERROR <io:0x7f5279007d90 fd=21 to=300000 fl=R tls=TLSv1.3:TLS_AES_256_GCM_SHA384:256 ib=0 ob=0>
4a4a947d0257ad3a smtp disconnected reason="io-error: error:0A080006:SSL routines::EVP lib"
...