Panic on Windows exit

[TACIXAT]

panic: The handle is invalid. [recovered]
        panic: The handle is invalid.

goroutine 74 [running]:
github.com/nsf/termbox-go.get_win_size(0x1e4, 0xc0004319e0)
        /home/dg/go/src/github.com/nsf/termbox-go/termbox_windows.go:448 +0xc4
github.com/nsf/termbox-go.update_size_maybe()
        /home/dg/go/src/github.com/nsf/termbox-go/termbox_windows.go:470 +0x38
github.com/nsf/termbox-go.Clear(0xc000000000, 0x729849, 0xc00025a9c0)
        /home/dg/go/src/github.com/nsf/termbox-go/api_windows.go:187 +0x41
github.com/nsf/termbox-go.Close()
        /home/dg/go/src/github.com/nsf/termbox-go/api_windows.go:77 +0x34
github.com/gizak/termui.Close()
        /home/dg/go/src/github.com/gizak/termui/render.go:75 +0x27
github.com/gizak/termui.render.func1()
        /home/dg/go/src/github.com/gizak/termui/render.go:104 +0x91
panic(0x73aee0, 0xc00000a038)
        /usr/local/go/src/runtime/panic.go:513 +0x1c7
github.com/nsf/termbox-go.get_win_size(0x1e4, 0xc00006f8f0)
        /home/dg/go/src/github.com/nsf/termbox-go/termbox_windows.go:448 +0xc4
github.com/nsf/termbox-go.update_size_maybe()
        /home/dg/go/src/github.com/nsf/termbox-go/termbox_windows.go:470 +0x38
github.com/nsf/termbox-go.Flush(0xaee4e8, 0xc00006fb60)
        /home/dg/go/src/github.com/nsf/termbox-go/api_windows.go:108 +0x2d
github.com/gizak/termui.render(0xc00029e210, 0x1, 0x1)
        /home/dg/go/src/github.com/gizak/termui/render.go:164 +0x1fb
github.com/gizak/termui.Init.func2()
        /home/dg/go/src/github.com/gizak/termui/render.go:65 +0x7a
created by github.com/gizak/termui.Init
        /home/dg/go/src/github.com/gizak/termui/render.go:63 +0x31e

[TACIXAT]

This causes the port to not get closed on the router. I'll add a flag for closing the default port from another client.