Revert "Fix for modular preview not functioning as expected #254"

This reverts commit a2275b8b73.

classes/controller.php

@@ -2001,12 +2001,6 @@ class AdminController
             $name .= '.md';
             $page->name($name);
             $page->template($type);
-
-            // unset some header things, template for now as we've just set that
-            if (isset($input['header']['template'])) {
-                unset($input['header']['template']);
-            }
-
         }
 
         // Special case for Expert mode: build the raw, unset content