go.talks: make static content application readable

jquery-ui.js is loaded at runtime. Now that it has moved to static/
(from js/) it must be application readable.

LGTM=dsymonds
R=golang-codereviews, dsymonds
CC=golang-codereviews
https://golang.org/cl/111650043
diff --git a/app.yaml b/app.yaml
index d6ca711..9c98af8 100644
--- a/app.yaml
+++ b/app.yaml
@@ -9,6 +9,7 @@
   upload: present/static/favicon.ico
 - url: /static
   static_dir: present/static
+  application_readable: true
 - url: /.*
   script: _go_app