Fix typo in querying events

[amaury1093]

Description

closes #8760

introduced in #8512 (comment), too bad the gogoproto-generated files don't export those as constants.

---

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• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer
• Review Codecov Report in the comment section below once CI passes

[codecov]

Codecov Report

Merging #8773 (f008249) into master (91affb5) will increase coverage by 0.00%.
The diff coverage is 90.90%.

@@           Coverage Diff           @@
##           master    #8773   +/-   ##
=======================================
  Coverage   61.38%   61.39%           
=======================================
  Files         672      672           
  Lines       38390    38404   +14     
=======================================
+ Hits        23565    23577   +12     
- Misses      12341    12342    +1     
- Partials     2484     2485    +1     

Impacted Files	Coverage Δ
x/staking/client/rest/query.go	40.66% <ø> (ø)
x/staking/types/msg.go	23.92% <ø> (ø)
x/ibc/core/02-client/types/encoding.go	60.00% <77.77%> (+6.15%)	⬆️
types/address.go	66.00% <100.00%> (+0.13%)	⬆️
x/ibc/core/02-client/keeper/client.go	98.27% <100.00%> (+0.06%)	⬆️