src/vs/platform/tunnel/common/tunnel.ts/AbstractTunnelService/defaultTunnelHost
class AbstractTunnelService:	protected get defaultTunnelHost(): string {
		const settingValue = this.configurationService.getValue('remote.localPortHost');
		return (!settingValue || settingValue === 'localhost') ? '127.0.0.1' : '0.0.0.0';
	}