Stop attempt at sending a spurious 404.

This was resulting in a bunch of "headers already sent" messages.

lib/www/server/api/index.js

@@ -365,7 +365,9 @@ app.use(function (err, req, res, next) {
 });
 
 app.get("*", (req, res, next) => {
-	res.status(404).send({status: 404, message: "This endpoint does not exist"});
+	if (!res.headersSent) {
+		res.status(404).send({status: 404, message: "This endpoint does not exist"});
+	}
 });
 
 app.disable('x-powered-by');