rpc: use GetBlockTime() for getblockchaininfo#time

src/rpc/blockchain.cpp

@@ -1208,7 +1208,7 @@ RPCHelpMan getblockchaininfo()
     obj.pushKV("headers", chainman.m_best_header ? chainman.m_best_header->nHeight : -1);
     obj.pushKV("bestblockhash", tip.GetBlockHash().GetHex());
     obj.pushKV("difficulty", GetDifficulty(&tip));
-    obj.pushKV("time", int64_t{tip.nTime});
+    obj.pushKV("time", tip.GetBlockTime());
     obj.pushKV("mediantime", tip.GetMedianTimePast());
     obj.pushKV("verificationprogress", GuessVerificationProgress(Params().TxData(), &tip));
     obj.pushKV("initialblockdownload", active_chainstate.IsInitialBlockDownload());