message: descriptor: fix missed m_script_arg arg renaming in
diff: @@ -492,9 +492,9 @@ public:
  if (!p->GetPrivKey(pos, provider, key)) continue;
  out.keys.emplace(key.GetPubKey().GetID(), key);
  }
  - if (m_script_arg) {
  + if (m_subdescriptor_arg) {
  FlatSigningProvider subprovider;
  - m_script_arg->ExpandPrivate(pos, provider, subprovider);
  + m_subdescriptor_arg->ExpandPrivate(pos, provider, subprovider);
  out = Merge(out, subprovider);
  }
  }
  