fix: exporting the blockParams regression (#13029)

## Description

Closes: #13024


---

### Author Checklist

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- [x] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [x] added `!` to the type prefix if API or client breaking change
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- [x] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
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- [ ] confirmed all CI checks have passed

### Reviewers Checklist

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your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed 
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- [ ] manually tested (if applicable)

server/export.go

@@ -82,8 +82,9 @@ func ExportCmd(appExporter types.AppExporter, defaultNodeHome string) *cobra.Com
 			doc.InitialHeight = exported.Height
 			doc.ConsensusParams = &tmproto.ConsensusParams{
 				Block: tmproto.BlockParams{
-					MaxBytes: exported.ConsensusParams.Block.MaxBytes,
-					MaxGas:   exported.ConsensusParams.Block.MaxGas,
+					MaxBytes:   exported.ConsensusParams.Block.MaxBytes,
+					MaxGas:     exported.ConsensusParams.Block.MaxGas,
+					TimeIotaMs: doc.ConsensusParams.Block.TimeIotaMs,
 				},
 				Evidence: tmproto.EvidenceParams{
 					MaxAgeNumBlocks: exported.ConsensusParams.Evidence.MaxAgeNumBlocks,
@@ -104,6 +105,7 @@ func ExportCmd(appExporter types.AppExporter, defaultNodeHome string) *cobra.Com
 			}
 
 			cmd.SetOut(cmd.OutOrStdout())
+			cmd.SetErr(cmd.OutOrStderr())
 			cmd.Println(string(sdk.MustSortJSON(encoded)))
 			return nil
 		},