Myst shutdown crash on Windows

[anjmao]

Killing myst gracefully on windows is crashing myst process.

Steps to reproduce.

1. Connect to VPN.
2. Disconnect.
3. Close app.

work:4222 removed
2020-06-01T12:45:50.624 WRN communication/nats/connection_wrap.go:86 > NATS: disconnected
2020-06-01T12:45:50.626 WRN communication/nats/connection_wrap.go:85 > NATS: connection closed
2020-06-01T12:45:50.624 INF firewall/outgoing_firewall_noop.go:61    > Rule for URL: nats://testnet-broker.mysterium.network:4222 removed
2020-06-01T12:45:50.627 ERR cmd/di.go:329                            > Dependencies shutdown failed error="failed to revert ICS IP-address range: Access is denied."
panic: close of closed channel

goroutine 1 [running]:
github.com/mysteriumnetwork/node/core/quality.(*MysteriumMORQA).Stop(0xc0000d3300)
        /Users/anjmao/go/src/github.com/mysteriumnetwork/node/core/quality/mysterium_morqa.go:139 +0x3a
github.com/mysteriumnetwork/node/cmd.(*Dependencies).Shutdown(0xc0005b2000, 0x1c06980, 0xc0008acf40)
        /Users/anjmao/go/src/github.com/mysteriumnetwork/node/cmd/di.go:366 +0x280
github.com/mysteriumnetwork/node/cmd/commands/daemon.NewCommand.func2(0xc00005f6c0, 0x2a, 0xc000a23c80)
        /Users/anjmao/go/src/github.com/mysteriumnetwork/node/cmd/commands/daemon/command.go:57 +0x31
github.com/urfave/cli/v2.(*Command).Run.func1(0xc0006f8c60, 0xc00005f6c0, 0xc000a23da8)
        /Users/anjmao/go/pkg/mod/github.com/urfave/cli/v2@v2.1.1/command.go:135 +0x42
github.com/urfave/cli/v2.(*Command).Run(0xc0006f8c60, 0xc00005f440, 0x1c073a0, 0xc000848d20)
        /Users/anjmao/go/pkg/mod/github.com/urfave/cli/v2@v2.1.1/command.go:166 +0x4e0
github.com/urfave/cli/v2.(*App).RunContext(0xc000049800, 0x1c26060, 0xc00002a0d8, 0xc00005e080, 0x3, 0x4, 0x0, 0x0)
        /Users/anjmao/go/pkg/mod/github.com/urfave/cli/v2@v2.1.1/app.go:302 +0x797
github.com/urfave/cli/v2.(*App).Run(...)
        /Users/anjmao/go/pkg/mod/github.com/urfave/cli/v2@v2.1.1/app.go:211
main.main()
        /Users/anjmao/go/src/github.com/mysteriumnetwork/node/cmd/mysterium_node/mysterium_node.go:56 +0x8e