Error then converting from Oserl

[saneery]

SMPPEX.Pdu.Oser.from/1 doesn't support CALLBACK_NUM field

** (Protocol.UndefinedError) protocol String.Chars not implemented for {:badarg, [{:erlang, :list_to_binary, [[{:callback_num, 1, 2, 1, 'MYSUPERNUMBER'}]], [error_info: %{module: :erl_erts_errors}]}, {SMPPEX.Pdu.Oserl, :list_to_string, 1, [file: 'lib/smppex/pdu/oserl.ex', line: 96]}, {Enum, :"-map/2-lists^map/1-0-", 2, [file: 'lib/enum.ex', line: 1593]}, {Enum, :"-map/2-lists^map/1-0-", 2, [file: 'lib/enum.ex', line: 1593]}, {SMPPEX.Pdu.Oserl, :from, 1, [file: 'lib/smppex/pdu/oserl.ex', line: 48]}

[savonarola]

Hello!

I doubt that anyone still supports this repo. However, the https://hex.pm/packages/smppex package is supported here: https://github.com/savonarola/smppex

A PR with a fix will be highly appreciated.