Replace the random char seed to global rand to avoid collision

[git-hulk]

#1727 changed the random string causing namespaces test fails.

This fixes #1728

[mapleFU]

Aha, so thats GetCurrentTime collision to many times...

I'll write a GetUUID64 instead. Lets check this in first

[mapleFU]

func RandString(min, max int, typ RandStringType) string {
	return RandStringWithSeed(min, max, typ, rand.Int63())
}

The change LGTM, however, would it better to change RandString as above? Since WithSeed should better have a stable output with the same seed.

[git-hulk]

func RandString(min, max int, typ RandStringType) string {
	return RandStringWithSeed(min, max, typ, rand.Int63())
}

The change LGTM, however, would it better to change RandString as above? Since WithSeed should better have a stable output with the same seed.

I changed the seed to rand.Int63. It's better than the time seed.