revert updated pdf worker and don't minify it

This reverts commit ffbf6f052f1800b55c7636a98e4f16fdf629c376.

services/web/Gruntfile.coffee

@@ -101,8 +101,6 @@ module.exports = (grunt) ->
 							exclude: ["libs"]
 						}, {
 							name: "libs"
-						},{
-							name: "libs/pdf.worker"
 						},{
 							name: "ace/mode-latex"
 						}