perf(calendar): Disable custom properties for individual calendar events

Save a query per event stored in the calendar and at least on the
production instance, there is no entries in the table for the events.

Signed-off-by: Carl Schwan <carl.schwan@nextclound.com>

apps/dav/lib/DAV/CustomPropertiesBackend.php

@@ -10,6 +10,7 @@ namespace OCA\DAV\DAV;
 
 use Exception;
 use OCA\DAV\CalDAV\Calendar;
+use OCA\DAV\CalDAV\CalendarObject;
 use OCA\DAV\CalDAV\DefaultCalendarValidator;
 use OCA\DAV\Connector\Sabre\Directory;
 use OCA\DAV\Connector\Sabre\FilesPlugin;
@@ -224,6 +225,11 @@ class CustomPropertiesBackend implements BackendInterface {
 			$this->cacheDirectory($path, $node);
 		}
 
+		if ($node instanceof CalendarObject) {
+			// No custom properties supported on individual events
+			return;
+		}
+
 		// First fetch the published properties (set by another user), then get the ones set by
 		// the current user. If both are set then the latter as priority.
 		foreach ($this->getPublishedProperties($path, $requestedProps) as $propName => $propValue) {