no null byte needed in message payload, so GNUNET_memcpy fits better

src/testbed/testbed_api.c

@@ -2014,9 +2014,9 @@ GNUNET_TESTBED_create_helper_init_msg_ (const char *trusted_ip,
   msg->config_size = htons (config_size);
   (void) strcpy ((char *) &msg[1], trusted_ip);
   if (0 != hostname_len)
-    /* intentionally use strncpy (no null byte needed) */
-    (void) strncpy (((char *) &msg[1]) + trusted_ip_len + 1, hostname,
-                    hostname_len);
+    GNUNET_memcpy (&msg[1] + trusted_ip_len + 1,
+                   hostname,
+                   hostname_len);
   return msg;
 }