Removed unused variables in shapes plugin

[ahcorde]

🦟 Bug fix

Summary

Removed unused variables in shapes plugin

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)
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[codecov]

Codecov Report

Merging #1321 (2b24890) into ign-gazebo3 (ebb3a9a) will decrease coverage by 0.00%.
The diff coverage is n/a.

@@               Coverage Diff               @@
##           ign-gazebo3    #1321      +/-   ##
===============================================
- Coverage        77.19%   77.19%   -0.01%     
===============================================
  Files              227      227              
  Lines            13578    13578              
===============================================
- Hits             10482    10481       -1     
- Misses            3096     3097       +1     

Impacted Files	Coverage Δ
src/gui/plugins/shapes/Shapes.cc	31.25% <ø> (ø)
src/Server.cc	84.33% <0.00%> (-0.61%)	⬇️

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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-2022-03-01-citadel-edifice-fortress/1313/1

[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-2022-04-13-fortress-edifice/1367/1