Merge #6618: refactor: various trivial fixes and dead code removals

e8de32c refactor: removed unused variable m_coinjoin_client (Konstantin Akimov)
542b2c8 chore: add src/dashbls/config.status.old to git-ignore list (Konstantin Akimov)
5033bde refactor: drop BIP16Height as have it always active on all chains (Konstantin Akimov)

Pull request description:

  ## What was done?
  See each commit

  ## How Has This Been Tested?
  Run unit / functional tests

  ## Breaking Changes
  N/A

  ## Checklist:
  - [x] I have performed a self-review of my own code
  - [x] I have commented my code, particularly in hard-to-understand areas
  - [ ] I have added or updated relevant unit/integration/functional/e2e tests
  - [ ] I have made corresponding changes to the documentation
  - [x] I have assigned this pull request to a milestone

ACKs for top commit:
  UdjinM6:
    utACK e8de32c
  kwvg:
    utACK e8de32c
  PastaPastaPasta:
    utACK e8de32c

Tree-SHA512: f1c7383559e2746d5fdbfa2ae33be86a7168648781d8a1682d547b65c1df1d25f908d3e25f0cfb4c49203277abd1ea8e358547c704e3af5c0d3363a1f4a290aa

Author: PastaPastaPasta

.gitignore

@@ -39,6 +39,7 @@ build-aux/test-driver
 config.cache
 config.log
 config.status
+config.status.old
 configure
 libtool
 src/config/bitcoin-config.h

src/chainparams.cpp

@@ -160,7 +160,6 @@ class CMainParams : public CChainParams {
     CMainParams() {
         strNetworkID = CBaseChainParams::MAIN;
         consensus.nSubsidyHalvingInterval = 210240; // Note: actual number of blocks per calendar year with DGW v3 is ~200700 (for example 449750 - 249050)
-        consensus.BIP16Height = 0;
         consensus.nMasternodePaymentsStartBlock = 100000; // not true, but it's ok as long as it's less then nMasternodePaymentsIncreaseBlock
         consensus.nMasternodePaymentsIncreaseBlock = 158000; // actual historical value
         consensus.nMasternodePaymentsIncreasePeriod = 576*30; // 17280 - actual historical value
@@ -358,7 +357,6 @@ class CTestNetParams : public CChainParams {
     CTestNetParams() {
         strNetworkID = CBaseChainParams::TESTNET;
         consensus.nSubsidyHalvingInterval = 210240;
-        consensus.BIP16Height = 0;
         consensus.nMasternodePaymentsStartBlock = 4010; // not true, but it's ok as long as it's less then nMasternodePaymentsIncreaseBlock
         consensus.nMasternodePaymentsIncreaseBlock = 4030;
         consensus.nMasternodePaymentsIncreasePeriod = 10;
@@ -532,7 +530,6 @@ class CDevNetParams : public CChainParams {
     explicit CDevNetParams(const ArgsManager& args) {
         strNetworkID = CBaseChainParams::DEVNET;
         consensus.nSubsidyHalvingInterval = 210240;
-        consensus.BIP16Height = 0;
         consensus.nMasternodePaymentsStartBlock = 4010; // not true, but it's ok as long as it's less then nMasternodePaymentsIncreaseBlock
         consensus.nMasternodePaymentsIncreaseBlock = 4030;
         consensus.nMasternodePaymentsIncreasePeriod = 10;
@@ -766,7 +763,6 @@ class CRegTestParams : public CChainParams {
     explicit CRegTestParams(const ArgsManager& args) {
         strNetworkID =  CBaseChainParams::REGTEST;
         consensus.nSubsidyHalvingInterval = 150;
-        consensus.BIP16Height = 0; // always enforce P2SH BIP16 on regtest
         consensus.nMasternodePaymentsStartBlock = 240;
         consensus.nMasternodePaymentsIncreaseBlock = 350;
         consensus.nMasternodePaymentsIncreasePeriod = 10;

src/consensus/params.h

@@ -97,7 +97,6 @@ struct Params {
     uint256 hashDevnetGenesisBlock;
     int nSubsidyHalvingInterval;
     /** Block height at which BIP16 becomes active */
-    int BIP16Height;
     int nMasternodePaymentsStartBlock;
     int nMasternodePaymentsIncreaseBlock;
     int nMasternodePaymentsIncreasePeriod; // in blocks

src/validation.cpp

@@ -2080,9 +2080,8 @@ static unsigned int GetBlockScriptFlags(const CBlockIndex* pindex, const Consens
     unsigned int flags = SCRIPT_VERIFY_NONE;
 
     // Start enforcing P2SH (BIP16)
-    if (pindex->nHeight >= consensusparams.BIP16Height) {
-        flags |= SCRIPT_VERIFY_P2SH;
-    }
+    // It always active on Dash chains
+    flags |= SCRIPT_VERIFY_P2SH;
 
     // Enforce the DERSIG (BIP66) rule
     if (DeploymentActiveAt(*pindex, consensusparams, Consensus::DEPLOYMENT_DERSIG)) {

src/wallet/interfaces.cpp

@@ -549,7 +549,6 @@ class WalletImpl : public Wallet
 
     WalletContext& m_context;
     std::shared_ptr<CWallet> m_wallet;
-    std::unique_ptr<interfaces::CoinJoin::Client> m_coinjoin_client;
 };
 
 class WalletLoaderImpl : public WalletLoader