Update Macbeth Dictionary

[wpwupingwp]

In Macbeth colorchecker dictionary, the RGB value of 21.neutral 6.5(.44*) and 23.neutral 3.5(.1.05*) seems to be wrong, while Lab values are correct.

Citation: https://babelcolor.com/index_htm_files/RGB%20Coordinates%20of%20the%20Macbeth%20ColorChecker.pdf

Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

• I agree to contribute to the project under Apache 2 License.
• To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
• The PR is proposed to the proper branch
• There is a reference to the original bug report and related work
• There is accuracy test, performance test and test data in opencv_extra repository, if applicable
  Patch to opencv_extra has the same branch name.
• The feature is well documented and sample code can be built with the project CMake

[vpisarev]

thank you! 👍