message: Hide 1px gray border when window has minimum size (win)
diff: <UserControl.InputBindings>
  <KeyBinding Key="Enter" Command="{Binding ConfirmLoginSignupCommand}" />
  </UserControl.InputBindings>
  - <Grid Background="{StaticResource ViewBackground}">
  + <Grid Background="{StaticResource ViewBackground}"
  + Margin="1">
  <Border BorderThickness="1"
  BorderBrush="{DynamicResource Toggl.LoginView.Border}"
  Width="300" Height="460"
  