Revert "Merge pull request microsoft#498: Use vscode.env.openExternal…

… to open browser windows when available"

This reverts commit 2908ec8, reversing
changes made to f76a76f.

src/helpers/utils.ts

@@ -6,7 +6,6 @@
 
 import { BuildResult } from "vso-node-api/interfaces/BuildInterfaces";
 import { Strings } from "./strings";
-import * as vscode from "vscode";
 
 import * as fs from "fs";
 import * as path from "path";
@@ -154,13 +153,6 @@ export class Utils {
 
     //Use open for Windows and Mac, opener for Linux
     public static OpenUrl(url: string) : void {
-        // Use the built in VS Code openExternal function if present.
-        if ((<any>vscode.env).openExternal) {
-            (<any>vscode.env).openExternal(vscode.Uri.parse(url));
-            return;
-        }
-
-        // Fallback to other node modules for old versions of VS Code
         switch (process.platform) {
             case "win32":
             case "darwin":