Issue: label with auto width in a flex container get 0 width

[Aiving]

When content: "flex" is used in an auto-sized label, the sizes of child elements using the flex(grow_factor) function start measuring their size incorrectly.

Code for reproduction:

use freya::prelude::*;

fn main() {
    launch(App);
}

#[component]
fn App() -> Element {
    rsx! {
        rect {
            width: "256",
            height: "48",
            padding: "12 5 12 5",
            background: "#999999",

            rect {
                direction: "horizontal",
                spacing: "8",
                cross_align: "center",
                content: "flex",

                rect {
                    width: "flex",
                    main_align: "center",

                    label { "Click Me!" }
                }

                rect {
                    width: "12",
                    height: "12",
                    background: "red",
                }
            }
        }
    }
}