Disable compression for DTLS.

The only standard compression method is stateful and is incompatible with
DTLS.
(cherry picked from commit e14b8410ca)

ssl/ssl_lib.c

@@ -1567,6 +1567,8 @@ SSL_CTX *SSL_CTX_new(SSL_METHOD *meth)
 	CRYPTO_new_ex_data(CRYPTO_EX_INDEX_SSL_CTX, ret, &ret->ex_data);
 
 	ret->extra_certs=NULL;
+	/* No compression for DTLS */
+	if (meth->version != DTLS1_VERSION)
 		ret->comp_methods=SSL_COMP_get_compression_methods();
 
 #ifndef OPENSSL_NO_TLSEXT