message: bench: put addrman check ratio in a variable
  So that it is easy to modify through the file `bench/addrman.cpp`.
diff: static constexpr size_t NUM_SOURCES = 64;
  static constexpr size_t NUM_ADDRESSES_PER_SOURCE = 256;
  +static const std::vector<bool> EMPTY_ASMAP;
  +static constexpr uint32_t ADDRMAN_CONSISTENCY_CHECK_RATIO{0};
  +
  static std::vector<CAddress> g_sources;
  static std::vector<std::vector<CAddress>> g_addresses;
  @@ -74,14 +77,14 @@ static void AddrManAdd(benchmark::Bench& bench)
  CreateAddresses();
  bench.run([&] {
  - AddrMan addrman{/* asmap */ std::vector<bool>(), /* deterministic */ false, /* consistency_check_ratio */ 0};
  + AddrMan addrman{EMPTY_ASMAP, /*deterministic=*/false, ADDRMAN_CONSISTENCY_CHECK_RATIO};
  AddAddressesToAddrMan(addrman);
  });
  }
  static void AddrManSelect(benchmark::Bench& bench)
  {
  - AddrMan addrman(/* asmap */ std::vector<bool>(), /* deterministic */ false, /* consistency_check_ratio */ 0);
  + AddrMan addrman{EMPTY_ASMAP, /*deterministic=*/false, ADDRMAN_CONSISTENCY_CHECK_RATIO};
  FillAddrMan(addrman);
  @@ -93,7 +96,7 @@ static void AddrManSelect(benchmark::Bench& bench)
  static void AddrManGetAddr(benchmark::Bench& bench)
  {
  - AddrMan addrman(/* asmap */ std::vector<bool>(), /* deterministic */ false, /* consistency_check_ratio */ 0);
  + AddrMan addrman{EMPTY_ASMAP, /*deterministic=*/false, ADDRMAN_CONSISTENCY_CHECK_RATIO};
  FillAddrMan(addrman);
  @@ -122,7 +125,7 @@ static void AddrManAddThenGood(benchmark::Bench& bench)
  //
  // This has some overhead (exactly the result of AddrManAdd benchmark), but that overhead is constant so improvements in
  // AddrMan::Good() will still be noticeable.
  - AddrMan addrman(/* asmap */ std::vector<bool>(), /* deterministic */ false, /* consistency_check_ratio */ 0);
  + AddrMan addrman{EMPTY_ASMAP, /*deterministic=*/false, ADDRMAN_CONSISTENCY_CHECK_RATIO};
  AddAddressesToAddrMan(addrman);
  markSomeAsGood(addrman);
  