Make sure the proper protocol is select in the account editor.
Replace pidgin_protocol_chooser_[gs]et_name with

pidgin_protocol_chooser_[gs]et_id.
Removed pidgin_protocol_store_finalize as it was only used

  to disconnect purple signals that we aren't using anymore.

Compiled and ran locally.  Verified via adding a new account, checking a connected account, and a disconnected account.