message: Add mainnet checkpoint, update tx stats
diff: @@ -214,14 +214,15 @@ public:
  {250000, uint256S("0x000000000000003887df1f29024b06fc2200b55f8af8f35453d7be294df2d214")},
  {279000, uint256S("0x0000000000000001ae8c72a0b0c301f67e3afca10e819efa9041e458e9bd7e40")},
  {295000, uint256S("0x00000000000000004d9b4ef50f0f9d686fd69db2e03af35a100370c64632a983")},
  + {640650, uint256S("0x000000059ec8884fa4fbbdbe46c09cfb4ecba281dfa2351a05084e817c1200ae")},
  }
  };
  chainTxData = ChainTxData{
  - // Data from rpc: getchaintxstats 4096 0000000000000000002e63058c023a9a1de233554f28c7b21380b6c9003f36a8
  - /* nTime */ 1532884444,
  - /* nTxCount */ 331282217,
  - /* dTxRate */ 2.4
  + // Data from rpc: getchaintxstats 4096 000000000c5dddd832b53e78d72f9f0d656d006bdf71a3de396e946e0799f197
  + /* nTime */ 1593660032,
  + /* nTxCount */ 266775998,
  + /* dTxRate */ 0.0072359
  };
  vPreminePubkeys = {
  