/wsapi/interaction_data should see the User Agent

lib/http_forward.js

@@ -90,6 +90,10 @@ exports.forward = function(dest, req, res, cb) {
     preq.setHeader('If-None-Match', req.headers['if-none-match']);
   }
 
+  if (req.headers['user-agent'] && '/wsapi/interaction_data' === req.path) {
+    preq.setHeader('User-Agent', req.headers['user-agent']);
+  }
+
   // if the body has already been parsed, we'll write it
   if (req.body) {
     var data;