Fix issue with undefined 'salesforce' variable.

An undefined Salesforce variable was causing an issue for developers who were choosing the local development option instead of the SF development option. This change resolves the problem.

generators/typescript/templates/webpack.config.js

@@ -8,7 +8,7 @@ const plugins = [];
 if (minimize) {
   plugins.push(new webpack.optimize.UglifyJsPlugin());
 }
-<% if(salesforce) { %> 
+<% if (!(typeof salesforce === 'undefined' || salesforce === null)) { %> 
   const coveoComponentMock = `
   <script src="../vendor/coveo/js/CoveoJsSearch.Lazy.js"></script>
   <script src="../vendor/coveo/js/templates/templates.js"></script>
@@ -23,7 +23,7 @@ if (minimize) {
 
 if (!production) {
   plugins.push(new webpack.HotModuleReplacementPlugin());
-  <% if(salesforce) { %>
+  <% if (!(typeof salesforce === 'undefined' || salesforce === null)) { %>
   plugins.push(new VisualforceHtmlPlugin({
     SalesforceContext: {
       CustomModifiers: {
@@ -62,4 +62,4 @@ module.exports = {
   },
   plugins: plugins,
   bail: true
-};
+};