MDL-57754 mod_lesson: Include missing required file

The constant LESSON_PAGE_BRANCHTABLE requires the page type file.

mod/lesson/locallib.php

@@ -683,7 +683,8 @@ function lesson_process_group_deleted_in_course($courseid, $groupid = null) {
  * @since  Moodle 3.3
  */
 function lesson_get_overview_report_table_and_data(lesson $lesson, $currentgroup) {
-    global $DB;
+    global $DB, $CFG;
+    require_once($CFG->dirroot . '/mod/lesson/pagetypes/branchtable.php');
 
     $context = $lesson->context;
     $cm = $lesson->cm;

mod/lesson/report.php

@@ -25,7 +25,6 @@
 
 require_once('../../config.php');
 require_once($CFG->dirroot.'/mod/lesson/locallib.php');
-require_once($CFG->dirroot.'/mod/lesson/pagetypes/branchtable.php'); // Needed for constant.
 
 $id     = required_param('id', PARAM_INT);    // Course Module ID
 $pageid = optional_param('pageid', null, PARAM_INT);    // Lesson Page ID