fix: rand seed for network check

[mzz2017]

Background

Every time check network using following list, it always performs in solid order.

dae/cmd/run.go

Lines 36 to 40 in 2a8f8f9

	CheckNetworkLinks = []string{
	"http://edge.microsoft.com/captiveportal/generate_204",
	"http://www.gstatic.com/generate_204",
	"http://www.qualcomm.cn/generate_204",
	}

Checklist

• The Pull Request has been fully tested

Full changelog

• Replace rand with fastrand, which uses seed in its init func.