small cleanup in a few places (#2058)

* move nStart closer to used and initialize it

* Quells warning displayed with `-Wmaybe-uninitialized` flag

* remove unused mnEntries vectors

* add devnet magic bytes to mininode.py

* remove unused governance-misc.h file

* remove old TODO comments

* replace map count/insert w/emplace in instantx.cpp

This feels like an optimization, something about:

```
if map.count(key)
     return false
else
     insert(pair)
     return true
```

... just feels icky. Plus, `vote.GetMasternodeOutpoint()` is only called
once. The previous version might be slightly more readable, however.

* Revert "replace map count/insert w/emplace in instantx.cpp"

This reverts commit d7f876e.

qa/rpc-tests/test_framework/mininode.py

@@ -1420,6 +1420,7 @@ class NodeConn(asyncore.dispatcher):
         "mainnet": b"\xbf\x0c\x6b\xbd",   # mainnet
         "testnet3": b"\xce\xe2\xca\xff",  # testnet3
         "regtest": b"\xfc\xc1\xb7\xdc",   # regtest
+        "devnet": b"\xe2\xca\xff\xce",    # devnet
     }
 
     def __init__(self, dstaddr, dstport, rpc, callback, net="regtest", services=NODE_NETWORK, send_version=True):

src/governance-object.cpp

@@ -710,11 +710,8 @@ void CGovernanceObject::UpdateSentinelVariables()
 
     // CALCULATE THE MINUMUM VOTE COUNT REQUIRED FOR FULL SIGNAL
 
-    // todo - 12.1 - should be set to `10` after governance vote compression is implemented
     int nAbsVoteReq = std::max(Params().GetConsensus().nGovernanceMinQuorum, nMnCount / 10);
     int nAbsDeleteReq = std::max(Params().GetConsensus().nGovernanceMinQuorum, (2 * nMnCount) / 3);
-    // todo - 12.1 - Temporarily set to 1 for testing - reverted
-    //nAbsVoteReq = 1;
 
     // SET SENTINEL FLAGS TO FALSE
 

src/init.cpp

@@ -1372,8 +1372,6 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
             return InitError(_("Unable to start HTTP server. See debug log for details."));
     }
 
-    int64_t nStart;
-
     // ********************************************************* Step 5: Backup wallet and verify wallet database integrity
 #ifdef ENABLE_WALLET
     if (!CWallet::InitAutoBackup())
@@ -1600,6 +1598,8 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
     LogPrintf("* Using %.1fMiB for in-memory UTXO set (plus up to %.1fMiB of unused mempool space)\n", nCoinCacheUsage * (1.0 / 1024 / 1024), nMempoolSizeMax * (1.0 / 1024 / 1024));
 
     bool fLoaded = false;
+    int64_t nStart = GetTimeMillis();
+
     while (!fLoaded && !fRequestShutdown) {
         bool fReset = fReindex;
         std::string strLoadError;

src/rpc/governance.cpp

@@ -427,9 +427,6 @@ UniValue gobject(const JSONRPCRequest& request)
         int nSuccessful = 0;
         int nFailed = 0;
 
-        std::vector<CMasternodeConfig::CMasternodeEntry> mnEntries;
-        mnEntries = masternodeConfig.getEntries();
-
         UniValue resultsObj(UniValue::VOBJ);
 
         for (const auto& mne : masternodeConfig.getEntries()) {
@@ -539,9 +536,6 @@ UniValue gobject(const JSONRPCRequest& request)
         int nSuccessful = 0;
         int nFailed = 0;
 
-        std::vector<CMasternodeConfig::CMasternodeEntry> mnEntries;
-        mnEntries = masternodeConfig.getEntries();
-
         UniValue resultsObj(UniValue::VOBJ);
 
         for (const auto& mne : masternodeConfig.getEntries())

src/rpc/masternode.cpp

@@ -770,9 +770,6 @@ UniValue masternodebroadcast(const JSONRPCRequest& request)
             EnsureWalletIsUnlocked();
         }
 
-        std::vector<CMasternodeConfig::CMasternodeEntry> mnEntries;
-        mnEntries = masternodeConfig.getEntries();
-
         int nSuccessful = 0;
         int nFailed = 0;
 
@@ -946,4 +943,4 @@ void RegisterMasternodeRPCCommands(CRPCTable &t)
 {
     for (unsigned int vcidx = 0; vcidx < ARRAYLEN(commands); vcidx++)
         t.appendCommand(commands[vcidx].name, &commands[vcidx]);
-}
+}