Fix trivial typo in command line help message

[nkoenig]

Signed-off-by: Nate Koenig [email protected]

🦟 Bug fix

Summary

Redo of #188

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

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[codecov]

Codecov Report

Merging #191 (63e4c17) into ign-msgs5 (bf0db74) will not change coverage.
The diff coverage is n/a.

❗ Current head 63e4c17 differs from pull request most recent head 80465af. Consider uploading reports for the commit 80465af to get more accurate results

@@            Coverage Diff             @@
##           ign-msgs5     #191   +/-   ##
==========================================
  Coverage      84.38%   84.38%           
==========================================
  Files              7        7           
  Lines            807      807           
==========================================
  Hits             681      681           
  Misses           126      126           

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[osrf-triage]

This pull request has been mentioned on Gazebo Community. There might be relevant details there:

https://community.gazebosim.org/t/new-ignition-releases-2022-01-10/1228/1

[osrf-triage]

This pull request has been mentioned on Gazebo Community. There might be relevant details there:

https://community.gazebosim.org/t/new-ignition-releases-2022-03-25-fortress-edifice-citadel/1343/1