chainparams: add signet assumeutxo param at height 160_000

Author: Sjors

src/kernel/chainparams.cpp

@@ -375,6 +375,15 @@ class SigNetParams : public CChainParams {
 
         vFixedSeeds.clear();
 
+        m_assumeutxo_data = {
+            {
+                .height = 160'000,
+                .hash_serialized = AssumeutxoHash{uint256S("0x5225141cb62dee63ab3be95f9b03d60801f264010b1816d4bd00618b2736e7be")},
+                .nChainTx = 2289496,
+                .blockhash = uint256S("0x0000003ca3c99aff040f2563c2ad8f8ec88bd0fd6b8f0895cfaf1ef90353a62c")
+            }
+        };
+
         base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,111);
         base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,196);
         base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1,239);