added self destruct function

contracts/FoolsGrans.sol

@@ -91,6 +91,10 @@ contract FoolsGrans is IERC20, Owned {
         emit FrozenFunds(target, freeze);
     }
 
+    function destroy() public onlyContractOwner {
+        selfdestruct(payable(contractOwner));
+    }
+
     /* This unnamed function is called whenever someone tries to send ether to it */
     fallback () external {
         revert();     // Prevents accidental sending of ether