nodejs/macos example:Add missing connect statement

Author: anandkumarpatel

samples/tutorials/node.js/macOS/SqlServerSample/connect.js

@@ -20,4 +20,7 @@ connection.on('connect', function(err) {
   } else {
     console.log('Connected');
   }
-});
+});
+
+// Initialize the connection.
+connection.connect();