fix: Fix v5 upgrade VE handler (#1468) (#1469)

* Add nil protections on upgrade handler

* Fix import name

* Address comment

(cherry picked from commit 5e002ee)

Co-authored-by: Eric Warehime <eric.warehime@gmail.com>

protocol/app/upgrades/v5.0.0/upgrade.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"math/big"
 
+	tenderminttypes "github.com/cometbft/cometbft/proto/tendermint/types"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	consensustypes "github.com/cosmos/cosmos-sdk/x/consensus/types"
 
@@ -263,15 +264,12 @@ func voteExtensionsUpgrade(
 	keeper consensusparamkeeper.Keeper,
 ) {
 	currentParams, err := keeper.Params(ctx, &consensustypes.QueryParamsRequest{})
-	if err != nil {
+	if err != nil || currentParams == nil || currentParams.Params == nil {
 		panic(fmt.Sprintf("failed to retrieve existing consensus params in VE upgrade handler: %s", err))
 	}
-	if currentParams.Params.Abci.VoteExtensionsEnableHeight != 0 {
-		panic(fmt.Sprintf(
-			"unable to update VE Enable Height since its current value of %d is already non-zero",
-			currentParams.Params.Abci.VoteExtensionsEnableHeight))
+	currentParams.Params.Abci = &tenderminttypes.ABCIParams{
+		VoteExtensionsEnableHeight: ctx.BlockHeight() + VEEnableHeightDelta,
 	}
-	currentParams.Params.Abci.VoteExtensionsEnableHeight = ctx.BlockHeight() + VEEnableHeightDelta
 	_, err = keeper.UpdateParams(ctx, &consensustypes.MsgUpdateParams{
 		Authority: keeper.GetAuthority(),
 		Block:     currentParams.Params.Block,