docs(cookbook/graphql): remove old rxjs import files from guide

Author: Urigo

public/docs/ts/latest/cookbook/graphql.jade

@@ -410,14 +410,12 @@ block file-summary
    `heroes-graphql/ts/app/app-routing.module.ts,
     heroes-graphql/ts/app/hero-search.component.ts,
     heroes-graphql/ts/app/hero-search.component.html,
-    heroes-graphql/ts/app/hero-search.component.css,
-    heroes-graphql/ts/app/rxjs-extensions.ts`,
+    heroes-graphql/ts/app/hero-search.component.css
     null,
    `app-routing.modules.ts,
     hero-search.component.ts,
     hero-search.component.html,
-    hero-search.component.css,
-    rxjs-extensions.ts`
+    hero-search.component.css
   )
 
 :marked