do not generate a mail if no shared file

Signed-off-by: Maxence Lange <maxence@artificial-owl.com>

Author: ArtificialOwl

lib/GlobalScale/MemberAdd.php

@@ -199,7 +199,7 @@ public function result(array $events): void {
 			}
 		}
 
-		if ($circle === null || $member === null) {
+		if (empty($links) || $circle === null || $member === null) {
 			return;
 		}