Reset ret in client and server after wolfSSL_dtls_got_timeout()

- Do UDP connect only with simulateWantWrite to accommodate macOS that doesn't like sendto being called on connected UDP sockets
- Call wolfSSL_dtls_get_current_timeout only on a DTLS connection

examples/server/server.c

@@ -330,7 +330,8 @@ static int NonBlockingSSL_Accept(SSL* ssl)
             }
             else {
             #ifdef WOLFSSL_DTLS
-                currTimeout = wolfSSL_dtls_get_current_timeout(ssl);
+                if (wolfSSL_dtls(ssl))
+                    currTimeout = wolfSSL_dtls_get_current_timeout(ssl);
             #endif
                 select_ret = tcp_select(sockfd, currTimeout);
             }
@@ -360,6 +361,7 @@ static int NonBlockingSSL_Accept(SSL* ssl)
                 error = wolfSSL_get_error(ssl, ret);
             else
                 error = WOLFSSL_ERROR_WANT_READ;
+            ret = WOLFSSL_FAILURE; /* Reset error so we loop */
         }
     #endif
         else {