Don't emit error twice from http.Client

lib/http.js

@@ -679,10 +679,7 @@ function Client ( ) {
   };
 
   self.addListener("close", function (e) {
-    if (e) {
-      self.emit("error", e);
-      return;
-    }
+    if (e) return;
 
     debug("HTTP CLIENT onClose. readyState = " + self.readyState);