Fix downstream Windows builds

[chapulina]

Signed-off-by: Louise Poubel [email protected]

Bug Fix

Summary

Downstream builds have been broken since #32 with:

CMake Error in loader/src/cmd/CMakeLists.txt:
  Evaluation file to be written multiple times with different content.  This
  is generally caused by the content evaluating the configuration type,
  language, or location of object files:

   D:/Jenkins/workspace/ign_gazebo-ci-win/ws/build/ignition-plugin1/test/lib/ruby/ignition/cmdplugin1.rb


CMake Error in loader/src/cmd/CMakeLists.txt:
  Evaluation file to be written multiple times with different content.  This
  is generally caused by the content evaluating the configuration type,
  language, or location of object files:

   D:/Jenkins/workspace/ign_gazebo-ci-win/ws/build/ignition-plugin1/test/lib/ruby/ignition/cmdplugin1.rb

I noticed this library is following SDFormat's example, and command line tools are disabled on Windows there, so I'm doing the same here to fix the build.

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

Note to maintainers: Remember to use Squash-Merge

[codecov]

Codecov Report

Merging #38 (fa67f30) into ign-plugin1 (88636ce) will not change coverage.
The diff coverage is n/a.

@@             Coverage Diff              @@
##           ign-plugin1      #38   +/-   ##
============================================
  Coverage        99.82%   99.82%           
============================================
  Files               15       15           
  Lines              584      584           
============================================
  Hits               583      583           
  Misses               1        1           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 88636ce...fa67f30. Read the comment docs.