Handle board exceptions more gracefully

Signed-off-by: Julius Härtl <jus@bitgrid.net>

lib/Service/PermissionService.php

@@ -333,4 +333,13 @@ class PermissionService {
 		}
 		return $groups;
 	}
+
+	/**
+	 * Set a different user than the current one, e.g. when no user is available in occ
+	 *
+	 * @param string $userId
+	 */
+	public function setUserId(string $userId): void {
+		$this->userId = $userId;
+	}
 }