Making usage of +v snomask

[pcho]

It would be useful to have snomaks +v display notices every time oper or bot with vhost oper privileges set a new vhost.

Sample +v notice:

irc.network.tld: -VHOST- username vhost set to domain.tld by operatorname

[pcho]

It wrongly shows changes: 10:17 -- | irc.tldr.chat: -VHOST- Operator marian set vhost marian on account techen.co taking username as vhost. :)