Fix regression from #6027

[teunbrand]

This PR fixes a regression introduced by #6027, that is detectable as:

ggplot2/revdep/problems.md

Lines 18570 to 18572 in d31c051

	7. └─self$coord$setup_params(data)
	8. └─ggplot2 (local) setup_params(..., self = self)
	9. └─ggplot2:::parse_coord_expand(expand = self$expand %||% TRUE)

The regression occurs when expand = 0 or expand = 1 is set in the coord, and this PR makes this valid input again.