Fix logic to require mandatory sidestaking in miner.cpp

If mandatory sidestakes that have non-zero allocation are set OR
local sidestakes with non-zero allocations are set and the
-enablesidestaking flag is turned on, then set
fEnableSideStaking in the miner to true to include sidestakes.

This replaces the old logic of fEnableSideStaking, which simply
followed -enablestidestaking.

src/miner.cpp

@@ -1334,12 +1334,15 @@ void StakeMiner(CWallet *pwallet)
         // nMinStakeSplitValue and dEfficiency are out parameters.
         bool fEnableStakeSplit = GetStakeSplitStatusAndParams(nMinStakeSplitValue, dEfficiency, nDesiredStakeOutputValue);
 
-        bool fEnableSideStaking = gArgs.GetBoolArg("-enablesidestaking");
-
         // Note that fEnableSideStaking is now processed internal to ActiveSideStakeEntries. The sidestaking flag only
         // controls local sidestakes. If there exists mandatory sidestakes, they occur regardless of the flag.
         vSideStakeAlloc = GRC::GetSideStakeRegistry().ActiveSideStakeEntries(false, false);
 
+        // If the vSideStakeAlloc is not empty, then set fEnableSideStaking to true. Note that vSideStakeAlloc will not be empty
+        // if non-zero allocation mandatory sidestakes are set OR local sidestaking is turned on by the -enablesidestaking config
+        // option.
+        bool fEnableSideStaking = (!vSideStakeAlloc.empty());
+
         // wait for next round
         if (!MilliSleep(nMinerSleep)) return;