fix: close cursor after reading the invitation

Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>

apps/dav/lib/Controller/InvitationResponseController.php

@@ -171,6 +171,7 @@ private function getTokenInformation(string $token) {
 			->where($query->expr()->eq('token', $query->createNamedParameter($token)));
 		$stmt = $query->execute();
 		$row = $stmt->fetch(\PDO::FETCH_ASSOC);
+		$stmt->closeCursor();
 
 		if (!$row) {
 			return null;