unit_tests: fix build after get_output_distribution signature change

tests/unit_tests/hardfork.cpp

@@ -112,7 +112,7 @@ public:
   virtual bool for_all_outputs(std::function<bool(uint64_t amount, const crypto::hash &tx_hash, uint64_t height, size_t tx_idx)> f) const { return true; }
   virtual bool for_all_outputs(uint64_t amount, const std::function<bool(uint64_t height)> &f) const { return true; }
   virtual bool is_read_only() const { return false; }
-  virtual std::map<uint64_t, std::tuple<uint64_t, uint64_t, uint64_t>> get_output_histogram(const std::vector<uint64_t> &amounts, bool unlocked, uint64_t recent_cutoff) const { return std::map<uint64_t, std::tuple<uint64_t, uint64_t, uint64_t>>(); }
+  virtual std::map<uint64_t, std::tuple<uint64_t, uint64_t, uint64_t>> get_output_histogram(const std::vector<uint64_t> &amounts, bool unlocked, uint64_t recent_cutoff, uint64_t min_count) const { return std::map<uint64_t, std::tuple<uint64_t, uint64_t, uint64_t>>(); }
 
   virtual void add_txpool_tx(const transaction &tx, const txpool_tx_meta_t& details) {}
   virtual void update_txpool_tx(const crypto::hash &txid, const txpool_tx_meta_t& details) {}