expander: Use the right state when querying style properties
expander: Use the right state when querying style properties

Failure to do so causes warnings.

grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita