Update defaultAssumeValid according to release-process.md.

Updated for block 506067 (0000000000000000005214481d2d96f898e3d5416e43359c145944a909d242e0).

src/chainparams.cpp

@@ -102,10 +102,10 @@ public:
         consensus.vDeployments[Consensus::DEPLOYMENT_SEGWIT].nTimeout = 1510704000; // November 15th, 2017.
 
         // The best chain should have at least this much work.
-        consensus.nMinimumChainWork = uint256S("0x000000000000000000000000000000000000000000723d3581fe1bd55373540a");
+        consensus.nMinimumChainWork = uint256S("0x000000000000000000000000000000000000000000f91c579d57cad4bc5278cc");
 
         // By default assume that the signatures in ancestors of this block are valid.
-        consensus.defaultAssumeValid = uint256S("0x0000000000000000003b9ce759c2a087d52abc4266f8f4ebd6d768b89defa50a"); //477890
+        consensus.defaultAssumeValid = uint256S("0x0000000000000000005214481d2d96f898e3d5416e43359c145944a909d242e0"); //506067
 
         /**
          * The message start string is designed to be unlikely to occur in normal data.