Fix twitter auth behind proxy

lib/services/twitter.js

@@ -18,7 +18,8 @@ function Twitter(options) {
 Twitter.prototype = new EventEmitter
 
 Twitter.prototype.parseURI = function(request) {
-  var protocol = request.socket.encrypted ? "https" : "http"
+  var proto = (request.headers["x-forwarded-proto"] || "").toLowerCase()
+    , protocol = request.socket.encrypted || proto == 'https' ? "https" : "http"
     , host = request.headers.host || request.connection.remoteAddress
 
   return url.parse(protocol + "://" + host + request.url, true)