TT#179901 api SMS remove obsolete rpc part from session

* session->rpc is not in use anymore and had $parts there which
  was a leftover from the inew billing cleanup and moving $session
  into the Controller/API/SMS

Change-Id: I6d9612cd3f3cbc57fe1b7df6584ad779dca64288

lib/NGCP/Panel/Controller/API/SMS.pm

@@ -129,7 +129,6 @@ sub create_item {
         reason => 'accepted',
         parts  => [],
         sid    => $session_id,
-        rpc    => $parts,
         coding => undef,
     };