message: Remove irreversible_block_age check
diff: @@ -648,9 +648,6 @@ producer_plugin_impl::start_block_result producer_plugin_impl::start_block() {
  } else if ( _pause_production ) {
  elog("Not producing block because production is explicitly paused");
  _pending_block_mode = pending_block_mode::speculating;
  - } else if ( irreversible_block_age >= _max_irreversible_block_age_us ) {
  - elog("Not producing block because the irreversible block is too old [age:${age}s, max:${max}s]", ("age", irreversible_block_age.count() / 1'000'000)( "max", _max_irreversible_block_age_us.count() / 1'000'000 ));
  - _pending_block_mode = pending_block_mode::speculating;
  }
  if (_pending_block_mode == pending_block_mode::producing) {
  