MDL-9367 restore: Roll only configuration dates

It was decided to roll only configuration dates and any date related to user content
such as 'timecreated' , 'timemodified' etc should not be rolled forward.

mod/label/lib.php

@@ -156,6 +156,10 @@ function label_get_coursemodule_info($coursemodule) {
  * @return array status array
  */
 function label_reset_userdata($data) {
+
+    // Any changes to the list of dates that needs to be rolled should be same during course restore and course reset.
+    // See MDL-9367.
+
     return array();
 }