[css-color-5] <hue-interpolation-method> error occurs at parse time

Author: cdoublev

css-color-5/Overview.bs

@@ -250,9 +250,6 @@ After normalizing both percentages, the result is produced via the following alg
 	[[css-color-4#hue-interpolation]].
 	If no <<hue-interpolation-method>> is specified, it is as if
 	''shorter'' had been specified.
-	If the specified color space is a
-	''rectangular-orthogonal-color'' space,
-	then specifying a <<hue-interpolation-method>> is an error.
 3. If an alpha multiplier was produced during percentage normalization,
 	the alpha component of the interpolated result is multiplied
 	by the alpha multiplier.