fix(arbitration): bug resolution

Author: hurstelm

contracts/src/arbitration/KlerosCoreBase.sol

@@ -210,7 +210,7 @@ abstract contract KlerosCoreBase is IArbitratorV2, Initializable, UUPSProxiable
         pinakion = _pinakion;
         jurorProsecutionModule = _jurorProsecutionModule;
         sortitionModule = _sortitionModuleAddress;
-        _wNative = wNative;
+        wNative = _wNative;
 
         // NULL_DISPUTE_KIT: an empty element at index 0 to indicate when a dispute kit is not supported.
         disputeKits.push();