[fix] Respect maxSockets from target options in RoutingProxy

Author: mmalecki

lib/node-http-proxy/routing-proxy.js

@@ -42,6 +42,7 @@ var RoutingProxy = exports.RoutingProxy = function (options) {
   //
   this.target = {};
   this.target.https = options.target && options.target.https;
+  this.target.maxSockets = options.target && options.target.maxSockets;
 
   //
   // Setup other default options to be used for instances of
@@ -91,6 +92,7 @@ RoutingProxy.prototype.add = function (options) {
   options.target.socketPath = options.target.socketPath || options.socketPath;
   options.target.https      = this.target && this.target.https ||
                               options.target && options.target.https;
+  options.target.maxSockets = this.target && this.target.maxSockets;
 
   //
   // Setup options to pass-thru to the new `HttpProxy` instance