refactor: Remove unused nchaintx from SnapshotMetadata constructor

Also, remove wrong nChainTx comment and cast.

Author: MarcoFalke

src/node/utxo_snapshot.h

@@ -35,8 +35,7 @@ class SnapshotMetadata
     SnapshotMetadata() { }
     SnapshotMetadata(
         const uint256& base_blockhash,
-        uint64_t coins_count,
-        unsigned int nchaintx) :
+        uint64_t coins_count) :
             m_base_blockhash(base_blockhash),
             m_coins_count(coins_count) { }
 

src/rpc/blockchain.cpp

@@ -2667,7 +2667,7 @@ UniValue CreateUTXOSnapshot(
         tip->nHeight, tip->GetBlockHash().ToString(),
         fs::PathToString(path), fs::PathToString(temppath)));
 
-    SnapshotMetadata metadata{tip->GetBlockHash(), maybe_stats->coins_count, tip->nChainTx};
+    SnapshotMetadata metadata{tip->GetBlockHash(), maybe_stats->coins_count};
 
     afile << metadata;
 
@@ -2694,9 +2694,7 @@ UniValue CreateUTXOSnapshot(
     result.pushKV("base_height", tip->nHeight);
     result.pushKV("path", path.u8string());
     result.pushKV("txoutset_hash", maybe_stats->hashSerialized.ToString());
-    // Cast required because univalue doesn't have serialization specified for
-    // `unsigned int`, nChainTx's type.
-    result.pushKV("nchaintx", uint64_t{tip->nChainTx});
+    result.pushKV("nchaintx", tip->nChainTx);
     return result;
 }