fix: remove user part only at the beginning of path

Signed-off-by: Salvatore Martire <4652631+salmart-dev@users.noreply.github.com>

Author: salmart-dev

lib/Sharing/DeckShareProvider.php

@@ -752,8 +752,9 @@ private function _getSharedWith(
 			}
 
 			if ($path !== null) {
-				if (str_starts_with($path, '/' . $userId . '/files')) {
-					$path = substr($path, strlen('/' . $userId . '/files'));
+				$prefix = '/' . $userId . '/files';
+				if (str_starts_with($path, $prefix)) {
+					$path = substr($path, strlen($prefix));
 				}
 				$path = rtrim($path, '/');