Remove -feefilter option

Feefilter option is debug only and it isn't used in any tests, it's wasteful
to check this option for every peer on every iteration of the message handler
loop. refs #21545

Author: amadeuszpawlik

src/init.cpp

@@ -390,7 +390,6 @@ void SetupServerArgs(NodeContext& node)
     argsman.AddArg("-datadir=<dir>", "Specify data directory", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
     argsman.AddArg("-dbbatchsize", strprintf("Maximum database write batch size in bytes (default: %u)", nDefaultDbBatchSize), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::OPTIONS);
     argsman.AddArg("-dbcache=<n>", strprintf("Maximum database cache size <n> MiB (%d to %d, default: %d). In addition, unused mempool memory is shared for this cache (see -maxmempool).", nMinDbCache, nMaxDbCache, nDefaultDbCache), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
-    argsman.AddArg("-feefilter", strprintf("Tell other nodes to filter invs to us by our mempool min fee (default: %u)", DEFAULT_FEEFILTER), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::OPTIONS);
     argsman.AddArg("-includeconf=<file>", "Specify additional configuration file, relative to the -datadir path (only useable from configuration file, not command line)", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
     argsman.AddArg("-loadblock=<file>", "Imports blocks from external file on startup", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
     argsman.AddArg("-maxmempool=<n>", strprintf("Keep the transaction memory pool below <n> megabytes (default: %u)", DEFAULT_MAX_MEMPOOL_SIZE), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);

src/net_processing.cpp

@@ -4711,7 +4711,6 @@ bool PeerManagerImpl::SendMessages(CNode* pto)
         if (pto->m_tx_relay != nullptr &&
             !m_ignore_incoming_txs &&
             pto->GetCommonVersion() >= FEEFILTER_VERSION &&
-            gArgs.GetBoolArg("-feefilter", DEFAULT_FEEFILTER) &&
             !pto->HasPermission(NetPermissionFlags::ForceRelay) // peers with the forcerelay permission should not filter txs to us
         ) {
             CAmount currentFilter = m_mempool.GetMinFee(gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000).GetFeePerK();

src/validation.h

@@ -82,8 +82,6 @@ static constexpr bool DEFAULT_COINSTATSINDEX{false};
 static const char* const DEFAULT_BLOCKFILTERINDEX = "0";
 /** Default for -persistmempool */
 static const bool DEFAULT_PERSIST_MEMPOOL = true;
-/** Default for using fee filter */
-static const bool DEFAULT_FEEFILTER = true;
 /** Default for -stopatheight */
 static const int DEFAULT_STOPATHEIGHT = 0;
 /** Block files containing a block-height within MIN_BLOCKS_TO_KEEP of ::ChainActive().Tip() will not be pruned. */