Add msg update contract label (backport #1640)

[mergify]

This is an automatic backport of pull request #1640 done by Mergify.
Cherry-pick of e654808 has failed:

On branch mergify/bp/releases/v0.4x/pr-1640
Your branch is up to date with 'origin/releases/v0.4x'.

You are currently cherry-picking commit e6548083.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   docs/proto/proto-docs.md
	modified:   proto/cosmwasm/wasm/v1/tx.proto
	modified:   x/wasm/client/cli/new_tx.go
	modified:   x/wasm/client/cli/tx.go
	modified:   x/wasm/keeper/keeper_test.go
	modified:   x/wasm/keeper/msg_server.go
	modified:   x/wasm/keeper/msg_server_integration_test.go
	modified:   x/wasm/types/codec.go
	modified:   x/wasm/types/events.go
	modified:   x/wasm/types/tx.go
	modified:   x/wasm/types/tx_test.go

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   x/wasm/keeper/keeper.go
	both modified:   x/wasm/types/tx.pb.go

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/github/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

---

Mergify commands and options

More conditions and actions can be found in the documentation.

You can also trigger Mergify actions by commenting on this pull request:

• @Mergifyio refresh will re-evaluate the rules
• @Mergifyio rebase will rebase this PR on its base branch
• @Mergifyio update will merge the base branch into this PR
• @Mergifyio backport <destination> will backport this PR on <destination> branch

Additionally, on Mergify dashboard you can:

• look at your merge queues
• generate the Mergify configuration with the config editor.

Finally, you can contact us on https://mergify.com

[codecov]

Codecov Report

Merging #1642 (793812e) into releases/v0.4x (03f3c72) will decrease coverage by 0.09%.
The diff coverage is 48.48%.

@@                Coverage Diff                 @@
##           releases/v0.4x    #1642      +/-   ##
==================================================
- Coverage           56.75%   56.67%   -0.09%     
==================================================
  Files                  64       64              
  Lines                8945     9011      +66     
==================================================
+ Hits                 5077     5107      +30     
- Misses               3478     3510      +32     
- Partials              390      394       +4     

Files	Coverage Δ
x/wasm/keeper/keeper.go	85.86% <100.00%> (-0.01%)	⬇️
x/wasm/types/codec.go	100.00% <100.00%> (ø)
x/wasm/types/events.go	0.00% <ø> (ø)
x/wasm/client/cli/tx.go	14.89% <0.00%> (-0.04%)	⬇️
x/wasm/keeper/msg_server.go	64.78% <57.14%> (-0.40%)	⬇️
x/wasm/types/tx.go	49.28% <47.05%> (-0.10%)	⬇️
x/wasm/client/cli/new_tx.go	0.00% <0.00%> (ø)