Fix no-dtls builds

Commits f2ff1432

 in master and 14d4d7eda in 1.1.0 broke the no-dtls build
by moving the position of a "#endif" for OPENSSL_NO_DTLS in a change
which is otherwise unrelated to DTLS. This puts it back to where it was.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2974)