htmlcs: H49 issues are marked as errors, but reference shows warning

[metsis]

For issues such as Principle1.Guideline1_3.1_3_1.H49. and Principle1.Guideline1_3.1_3_1.H49.AlignAttr kayle/htmlcs reports an error, whereas the htmlcs reference at https://squizlabs.github.io/HTML_CodeSniffer/Standards/WCAG2/ shows these to be warnings at all levels.

Why is there a mismatch here and is it intentional?

[j-mendez]

Need to check again, I think htmlcs had this incorrectly as a warning.