Clear devNetParams and mimic behavior of other param types (#2367)

* Clear devNetParams and mimic behavior of other param types

Mainnet, testnet and regtest params are global and thus zero initialized,
we should mimic the same for devnet params.

Not doing so results in all kinds of issues on devnet.

* Remove unnecessary <string.h> includein chainparamsbase.cpp

src/chainparams.cpp

@@ -722,7 +722,9 @@ CChainParams& Params(const std::string& chain)
 void SelectParams(const std::string& network)
 {
     if (network == CBaseChainParams::DEVNET) {
-        devNetParams = new CDevNetParams();
+        devNetParams = (CDevNetParams*)new uint8_t[sizeof(CDevNetParams)];
+        memset(devNetParams, 0, sizeof(CDevNetParams));
+        new (devNetParams) CDevNetParams();
     }
 
     SelectBaseParams(network);

src/chainparamsbase.cpp

@@ -109,7 +109,10 @@ void SelectBaseParams(const std::string& chain)
     if (chain == CBaseChainParams::DEVNET) {
         std::string devNetName = GetDevNetName();
         assert(!devNetName.empty());
-        devNetParams = new CBaseDevNetParams(devNetName);
+
+        devNetParams = (CBaseDevNetParams*)new uint8_t[sizeof(CBaseDevNetParams)];
+        memset(devNetParams, 0, sizeof(CBaseDevNetParams));
+        new (devNetParams) CBaseDevNetParams(devNetName);
     }
 
     pCurrentBaseParams = &BaseParams(chain);