MDL-28147 do not double cache theme css/js

theme/javascript.php

@@ -118,12 +118,11 @@ function send_uncached_js($js) {
 }
 
 function minify($files) {
-    global $CFG;
-
     if (0 === stripos(PHP_OS, 'win')) {
         Minify::setDocRoot(); // IIS may need help
     }
-    Minify::setCache('', true);
+    // disable all caching, we do it in moodle
+    Minify::setCache(null, false);
 
     $options = array(
         'bubbleCssImports' => false,