[ADMIN] ERROR: must be owner of extension plpgsql

Hi all,

Environment：

    Centos-6.5   pg-10.0

 I used common user to back up the data via pg_dump, then use the same user to restore ,but get the error:

ERROR:  must be owner of extension plpgsql

I found 'COMMENT ON EXTENSION plpgsql IS 'PL/pgSQL procedural language';' from the sql, it need superuser privilege ,why?