Ticket 47899: Fix slapi_td_plugin_lock_init prototype
    
    Description: FreeIPA compilation gives a GCC warning in a 389-ds header:
    warning: function declaration isn't a prototype
    Fixing the warning as follows:
      -int slapi_td_plugin_lock_init();
      +int slapi_td_plugin_lock_init(void);
    Note: () takes any number of arguments, while (void) takes none.
    
    (cherry picked from commit 3104346c574f17925c8113a30aa20116bf6a277c)