Keep only curent signer

Author: ranchalp

.gitmodules

@@ -10,3 +10,6 @@
 [submodule "lib/openzeppelin-contracts-upgradeable"]
 	path = lib/openzeppelin-contracts-upgradeable
 	url = https://github.com/OpenZeppelin/openzeppelin-contracts-upgradeable
+[submodule "lib/openzeppelin-contracts"]
+	path = lib/openzeppelin-contracts
+	url = https://github.com/OpenZeppelin/openzeppelin-contracts

lib/openzeppelin-contracts

@@ -1,9 +1,9 @@
 // SPDX-License-Identifier: MIT
 pragma solidity =0.8.24;
 
-import "@openzeppelin/contracts/access/OwnableUpgradable.sol";
+import "@openzeppelin/contracts/access/Ownable.sol";
 
-contract SystemConfig is OwnableUpgradable {
+contract SystemConfig is Ownable {
 
     address public currentSigner;