http: revert deprecation of client property

Reason: breaks a feature in the request module

lib/_http_incoming.js

@@ -15,6 +15,16 @@ function readStop(socket) {
 }
 exports.readStop = readStop;
 
+const deprecatedClientProperty = {
+  configurable: true,
+  enumerable: true,
+  get: util.deprecate(function() {
+    return this.socket;
+  }, 'http.IncomingMessage.client is deprecated, use .socket instead'),
+  set: util.deprecate(function(val) {
+    this.socket = val;
+  }, 'http.IncomingMessage.client is deprecated, use .socket instead')
+};
 
 /* Abstract base class for ServerRequest and ClientResponse. */
 function IncomingMessage(socket) {
@@ -47,7 +57,7 @@ function IncomingMessage(socket) {
   // response (client) only
   this.statusCode = null;
   this.statusMessage = null;
-  this._client = socket; // deprecated
+  Object.defineProperty(this, 'client', deprecatedClientProperty);
 
   // flag for backwards compatibility grossness.
   this._consuming = false;
@@ -61,16 +71,6 @@ util.inherits(IncomingMessage, Stream.Readable);
 
 exports.IncomingMessage = IncomingMessage;
 
-Object.defineProperty(IncomingMessage.prototype, 'client', {
-  configurable: true,
-  enumerable: true,
-  get: util.deprecate(function() {
-    return this._client;
-  }, 'client is deprecated, use socket or connection instead'),
-  set: util.deprecate(function(val) {
-    this._client = val;
-  }, 'client is deprecated, use socket or connection instead')
-});
 
 IncomingMessage.prototype.setTimeout = function(msecs, callback) {
   if (callback)