message: Shorten MAX_HISTORY_LEN default
diff: @@ -54,7 +54,7 @@ namespace ccf
  #ifdef OVERRIDE_MAX_HISTORY_LEN
  constexpr int MAX_HISTORY_LEN = OVERRIDE_MAX_HISTORY_LEN;
  #else
  - constexpr int MAX_HISTORY_LEN = 1000;
  + constexpr int MAX_HISTORY_LEN = 0;
  #endif
  static std::ostream& operator<<(std::ostream& os, HashOp flag)
  