When decoding Time with empty string, toggle IsSet

[rtgibbons]

cli/ext/decoders.go

Lines 51 to 55 in 205c0b8

	now := time.Now()
	if s == "" {
	t.Time = now
	return nil
	}

I think it makes sense to toggle IsSet to true here?

[suntong]

close via 238c6b9