Take IPv6 into account for the host variable

[vnxme]

There is a minor bug in the following line:

x-ui/web/controller/util.go

Line 64 in 1c32a91

data["host"] = strings.Split(c.Request.Host, ":")[0]

If c.Request.Host contains IPv4:port, then this line works correctly. But if this variable is [IPv6]:port, then this line takes a part of IPv6 with [ symbol at the beginning. E.g. for "[fcba:4:3:2::1]:80" data["host"] will be "[fcba".