message: Fix BFT memory issue
diff: @@ -466,8 +466,6 @@ namespace ccf
  crypto::KeyPair& kp;
  - std::map<RequestID, std::vector<uint8_t>> requests;
  -
  threading::Task::TimerEntry emit_signature_timer_entry;
  size_t sig_tx_interval;
  size_t sig_ms_interval;
  @@ -795,7 +793,6 @@ namespace ccf
  uint8_t frame_format) override
  {
  LOG_DEBUG_FMT("HISTORY: add_request {0}", id);
  - requests[id] = request;
  auto consensus = store.get_consensus();
  if (!consensus)
  