Remove vestigial parts of old minify code

(imported from commit 692e292528a1697687f1b3024c58371b2cf9b5c9)

zephyr/static/js/zephyr.js

@@ -1,8 +1,3 @@
-// zephyr/lib/minify.py will look for this comment in order to tell when it's
-// producing app.js:
-//
-// MINIFY-FILE-ID: zephyr.js
-
 var all_msg_list = new MessageList();
 var home_msg_list = new MessageList('zhome', new narrow.Filter([["in", "home"]]));
 var narrowed_msg_list;