title: NodeJS Axios setting header in axios request generates " Error: Parse Error: Invalid header value char"
body: <p>It doesn't matter what I set the header to, axios still generates an error.</p>
  <p>Code:</p>
  <pre><code>app.use(`/a/prx/*`, function(req, res) {
      const path = req.originalUrl.split(`/`).splice(-1).toString(); 
      var options = {
          url: `https://api.example.com/apis/${path}/`,
          method: req.method,
          headers: {
              &quot;User-Agent&quot;: &quot;Mozilla&quot;
              // really, I'd like to use req.headers[&quot;user-agent&quot;]
          }
      };
      axios(options)
          .then((responseFromServer2) =&gt; {
              // do good stuff
          })
          .catch((err) =&gt; {
              res.send(`ERROR: ${err}`);
          });
  });
  </code></pre>
  <p>I'd like to set the user-agent header to the original user-agent for tracking purposes but doing so generates an error.</p>