Enable ZIP209 on mainnet and set fallback Sprout pool balance.

src/chainparams.cpp

@@ -193,6 +193,14 @@ public:
                             //   total number of tx / (checkpoint block height / (24 * 24))
         };
 
+        // Hardcoded fallback value for the Sprout shielded value pool balance
+        // for nodes that have not reindexed since the introduction of monitoring
+        // in #2795.
+        nSproutValuePoolCheckpointHeight = 520633;
+        nSproutValuePoolCheckpointBalance = 22145062442933;
+        fZIP209Enabled = true;
+        hashSproutValuePoolCheckpointBlock = uint256S("0000000000c7b46b6bc04b4cbf87d8bb08722aebd51232619b214f7273f8460e");
+
         // Founders reward script expects a vector of 2-of-3 multisig addresses
         vFoundersRewardAddress = {
             "t3Vz22vK5z2LcKEdg16Yv4FFneEL1zg9ojd", /* main-index: 0*/