Fix file/dir group check

src/FusionDirectory/Tools/Setup.php

@@ -204,7 +204,7 @@ class Setup extends Cli\LdapApplication
 
       /* extract the owner and the group of the directory */
       $pwuid = posix_getpwuid($lstat['uid']);
-      $grgid = posix_getpwuid($lstat['gid']);
+      $grgid = posix_getgrgid($lstat['gid']);
       if (($pwuid === FALSE) || ($grgid === FALSE)) {
         throw new \Exception('Unable to read '.$dir.' ownership information'."\n");
       }