prevent queueing of proposals from different eras (#1196)

Co-authored-by: Akshat Mittal <[email protected]>

.solhintignore

@@ -20,3 +20,4 @@ contracts/vendor
 contracts/plugins/assets/compound/vendor
 contracts/plugins/assets/curve/crv
 contracts/plugins/assets/curve/cvx
+contracts/plugins/governance/vendor

contracts/plugins/governance/Governance.sol

@@ -1,13 +1,13 @@
 // SPDX-License-Identifier: BlueOak-1.0.0
 pragma solidity 0.8.19;
 
-import "@openzeppelin/contracts/governance/Governor.sol";
-import "@openzeppelin/contracts/governance/extensions/GovernorCountingSimple.sol";
-import "@openzeppelin/contracts/governance/extensions/GovernorSettings.sol";
-import "@openzeppelin/contracts/governance/extensions/GovernorTimelockControl.sol";
-import "@openzeppelin/contracts/governance/extensions/GovernorVotes.sol";
-import "@openzeppelin/contracts/governance/extensions/GovernorVotesQuorumFraction.sol";
 import "../../interfaces/IStRSRVotes.sol";
+import "./vendor/extensions/GovernorCountingSimple.sol";
+import "./vendor/extensions/GovernorSettings.sol";
+import "./vendor/extensions/GovernorTimelockControl.sol";
+import "./vendor/extensions/GovernorVotes.sol";
+import "./vendor/extensions/GovernorVotesQuorumFraction.sol";
+import "./vendor/Governor.sol";
 
 uint256 constant ONE_DAY = 86400; // {s}
 
@@ -183,7 +183,7 @@ contract Governance is
     // === Private ===
 
     function startedInSameEra(uint256 proposalId) private view returns (bool) {
-        uint256 startTimepoint = proposalSnapshot(proposalId);
+        uint256 startTimepoint = proposalProposedAt(proposalId);
         uint256 pastEra = IStRSRVotes(address(token)).getPastEra(startTimepoint);
         uint256 currentEra = IStRSRVotes(address(token)).currentEra();
         return currentEra == pastEra;