[fix] In routing proxy, match line beginning

Previous approach failed in case of routing table like:

    {
      'domain.com': 'localhost:9000',
      'a.domain.com': 'localhost:9001'
    }

without `hostnameOnly`. When routing request to `a.domain.com`,
`RegExp` matched first entry (`domain.com`) and returned it.

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

@@ -97,7 +97,7 @@ ProxyTable.prototype.setRoutes = function (router) {
  this.routes = [];
 
  Object.keys(router).forEach(function (path) {
- var route = new RegExp(path, 'i');
+ var route = new RegExp('^' + path, 'i');
 
  self.routes.push({
  route: route,
@@ -137,7 +137,6 @@ ProxyTable.prototype.getProxyLocation = function (req) {
  for (var i in this.routes) {
  var route = this.routes[i];
  if (target.match(route.route)) {
-
  var pathSegments = route.path.split('/');
 
  if (pathSegments.length > 1) {