fixed saving of calendar dates for course calendars

app/controllers/calendar/date.php

@@ -514,6 +514,9 @@ class Calendar_DateController extends AuthenticatedController
             if (($owner instanceof Course)) {
                 //Set the course as calendar:
                 $allowed_calendar_ids = [$owner->id];
+            } elseif (Context::isCourse()) {
+                //Set the course as allowed calendar:
+                $allowed_calendar_ids = [Context::getId()];
             } else {
                 //Assign the date to the calendars of all the selected users:
                 $allowed_calendar_ids = [$GLOBALS['user']->id];