Adding iconName to Button screw its automatic sizing

[Didier Roche-Tolomelli]

If you add an iconName to a button without a set width anchored to one side only, the sizing isn't correct.

Please find attached 2 screenshots demonstrating this issue: there are 2 buttons, one anchored to the left, the other anchored to the right.
If you set the iconName to anything, the right button will expand way beyond its needed width.

Minimal reproducer:

import QtQuick 2.4
import Ubuntu.Components 1.2

MainView {
    id: mainview
    objectName: "mainView"
    applicationName: "splitthebill.didrocks"

    width: units.gu(40)
    height: units.gu(75)

    Page {

        Button {
            text: "Reset"
            color: UbuntuColors.red
            anchors.left: parent.left
        }

        Button {
            iconName: "add"
            text: "Archive"
            color: UbuntuColors.green
            anchors.right: parent.right
        }
    }
}