MDL-52376 behat: Add 1 sec delay to ensure cron works

course completion record should be created at time
which is before the time cron is run. On fast machine
this both might be done at same time. So added 1 sec delay

completion/tests/behat/teacher_manual_completion.feature

@@ -41,12 +41,9 @@ Feature: Allow teachers to manually mark users as complete when configured
     And I follow "View course report"
     And I should see "Student First"
     And I follow "Click to mark user complete"
-    # Running cron just after clicking sometimes fail, so navigate back
-    # and ensure the student completion is updated before running cron.
-    And I am on site homepage
-    And I follow "Completion course"
-    And I follow "View course report"
-    And "//img[contains(@alt, 'Completed')]" "xpath_element" should exist in the "student1" "table_row"
+    # Running cron just after clicking sometimes fail, as record
+    # should be created before the cron runs.
+    And I wait "1" seconds
     And I trigger cron
     And I am on site homepage
     And I log out