mod_dialback: Remove d-w-d feature Backs out 1d0862814bfc and 2fdd71b08126 Largely unused, undocumented and did not have enough tests to provide confidence in its correct operation.

module:log("error", "mod_pep_plus has been renamed to mod_pep, please update your config file. Auto-loading mod_pep...");
module:depends("pep");