message: Remove unused block_trace
diff: @@ -46,13 +46,6 @@ namespace eosio { namespace chain {
  std::exception_ptr except_ptr;
  };
  - struct block_trace {
  - fc::microseconds elapsed;
  - uint64_t billed_cpu_usage_us;
  - vector<transaction_trace_ptr> trx_traces;
  - };
  - using block_trace_ptr = std::shared_ptr<block_trace>;
  -
  } } /// namespace eosio::chain
  FC_REFLECT( eosio::chain::base_action_trace,
  @@ -63,4 +56,3 @@ FC_REFLECT_DERIVED( eosio::chain::action_trace,
  FC_REFLECT( eosio::chain::transaction_trace, (id)(receipt)(elapsed)(net_usage)(scheduled)
  (action_traces)(failed_dtrx_trace)(except) )
  -FC_REFLECT( eosio::chain::block_trace, (elapsed)(billed_cpu_usage_us)(trx_traces) )
  