title: Timeout issue with express middleware
body: <p>I have a middleware which I using for token validation. Here is how it looks:</p>
  
  <pre><code>this.checkJwt =  jwt({
      secret: jwksRsa.expressJwtSecret({
          cache: true,
          rateLimit: true,
          jwksRequestsPerMinute: 5,
          jwksUri: process.env.AUTH0_JWKS,
      }),
      // Validate the audience and the issuer.
      audience: process.env.AUTH0_AUDIENCE,
      issuer: process.env.AUTH0_ISSUER,
  
      algorithms: ["RS256"],
  });
  </code></pre>
  
  <p>Then I apply it to use with my route:</p>
  
  <pre><code>app.route(routes.getUserInfo)
       .get(checkJwt, this.userController.me);
  </code></pre>
  
  <p>Why when I rewriting my middleware with <code>return</code> statement it stops working? Like this:</p>
  
  <pre><code>this.checkJwt = (req, res, next) =&gt; {
      return jwt({
          secret: jwksRsa.expressJwtSecret({
              cache: true,
              rateLimit: true,
              jwksRequestsPerMinute: 5,
              jwksUri: process.env.AUTH0_JWKS,
          }),
          // Validate the audience and the issuer.
          audience: process.env.AUTH0_AUDIENCE,
          issuer: process.env.AUTH0_ISSUER,
  
          algorithms: ["RS256"],
      });
  };
  </code></pre>
  
  <p>I got timeout exception with each request for this middleware. Seems like <code>next</code> function never touching.</p>