Do not try to set user scope for public share links (#755)

Do not try to set user scope for public share links

lib/Service/UserScopeService.php

@@ -41,7 +41,11 @@ class UserScopeService {
 	 * @param $uid
 	 * @throws \InvalidArgumentException
 	 */
-	public function setUserScope(string $uid) {
+	public function setUserScope(string $uid = null) {
+		if ($uid === null) {
+			return;
+		}
+
 		$user = $this->userManager->get($uid);
 		if ($user === null) {
 			throw new \InvalidArgumentException('No user found for the uid ' . $uid);