docs(toh-3): fix for empty tab (#2122)

Fixes #2119.

Author: chalin

public/docs/ts/latest/tutorial/toh-pt3.jade

@@ -225,7 +225,7 @@ code-example(format=".")
   toh-3/ts/app/hero-detail.component.ts,
   toh-3/ts/app/app.component.ts,
   toh-3/ts/app/hero.ts,
-  toh-3/ts/app/app.module.ts,
+  toh-3/ts/app/app.module.ts
   `,'',`
   app/hero-detail.component.ts,
   app/app.component.ts,