MetroCircleToggleButtonStyle BorderBrush not using Template Binding

[johanneswanzek]

MetroCircleToggleButtonStyle Ellipse used for MouseOver Border Effect not using BorderBrush Tempalte Binding.

https://github.com/MahApps/MahApps.Metro/blob/master/MahApps.Metro/Styles/Controls.Buttons.xaml

Line 648:
Stroke="#ADADAD"

Compared to MetroCircleButtonStyle
Line 103:
Stroke="{TemplateBinding BorderBrush}"

[punker76]

fixed with 1de3304