Fix DTLS certificate requesting code.

Use same logic when determining when to expect a client
certificate for both TLS and DTLS.

PR#3452

ssl/d1_srvr.c

@@ -616,10 +616,11 @@ int dtls1_accept(SSL *s)
 				s->state = SSL3_ST_SR_CLNT_HELLO_C;
 				}
 			else {
-				/* could be sent for a DH cert, even if we
-				 * have not asked for it :-) */
-				ret=ssl3_get_client_certificate(s);
-				if (ret <= 0) goto end;
+				if (s->s3->tmp.cert_request)
+					{
+					ret=ssl3_get_client_certificate(s);
+					if (ret <= 0) goto end;
+					}
 				s->init_num=0;
 				s->state=SSL3_ST_SR_KEY_EXCH_A;
 			}