Fix no-tls1_3
Fix no-tls1_3

The hostname_cb in sslapitest.c was originally only defined if TLSv1.3
was enabled. A recently added test now uses this unconditionally, so we
move the function implementation earlier in the file, and always compile
it in.

Reviewed-by: Richard Levitte <5fb523282dd7956571c80524edc2dccfa0bd8234@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/11014)

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl