Disable mining slow start in regtest mode

src/chainparams.cpp

@@ -210,6 +210,7 @@ class CRegTestParams : public CTestNetParams {
 public:
     CRegTestParams() {
         strNetworkID = "regtest";
+        consensus.nSubsidySlowStartInterval = 0;
         consensus.nSubsidyHalvingInterval = 150;
         consensus.nMajorityEnforceBlockUpgrade = 750;
         consensus.nMajorityRejectBlockOutdated = 950;