Merge pull request #4235 from nextcloud/backport-3857-legacy-caldav-endpoint-email-invitations

[stable11] Fix scheduling plugin on legacy caldav endpoint

Author: MorrisJobke

apps/dav/appinfo/v1/caldav.php

@@ -83,7 +83,7 @@
 
 $server->addPlugin(new \Sabre\DAV\Sync\Plugin());
 $server->addPlugin(new \Sabre\CalDAV\ICSExportPlugin());
-$server->addPlugin(new \Sabre\CalDAV\Schedule\Plugin());
+$server->addPlugin(new \OCA\DAV\CalDAV\Schedule\Plugin());
 $server->addPlugin(new \OCA\DAV\CalDAV\Schedule\IMipPlugin( \OC::$server->getMailer(), \OC::$server->getLogger()));
 $server->addPlugin(new ExceptionLoggerPlugin('caldav', \OC::$server->getLogger()));