Do not apply overwinter/sapling consensus rules to block 0

src/validationinterface.cpp

@@ -149,7 +149,7 @@ void ThreadNotifyWallets(CBlockIndex *pindexLastTip)
                 // the Sapling activation height. Otherwise, the last anchor was the
                 // empty root.
                 SaplingMerkleTree oldSaplingTree;
-                const bool sapling = true;
+                const bool sapling = pindex->pprev->GetHeight() >= 1 ? true : false;
                 if (sapling) { // NetworkUpgradeActive(pindex->pprev->GetHeight(),Params().GetConsensus(), Consensus::UPGRADE_SAPLING)) {
                     assert(pcoinsTip->GetSaplingAnchorAt(pindex->pprev->hashFinalSaplingRoot, oldSaplingTree));
                 } else {