MDL-63316 participants: lastname sort for participants table

user/classes/participants_table.php

@@ -220,8 +220,8 @@ class participants_table extends \table_sql {
         $this->define_columns($columns);
         $this->define_headers($headers);
 
-        // Make this table sorted by first name by default.
-        $this->sortable(true, 'firstname');
+        // Make this table sorted by last name by default.
+        $this->sortable(true, 'lastname');
 
         $this->no_sorting('select');
         $this->no_sorting('roles');

user/tests/behat/view_participants.feature

@@ -132,7 +132,6 @@ Feature: View course participants
     When I log in as "teacher1x"
     And I am on "Course 1" course homepage
     And I navigate to course participants
-    And I follow "Surname"
     And I click on "Select all" "checkbox"
     Then I should not see "Student 9x"
     And the field "Select 'Teacher 1x'" matches value "1"