Assume [] surround an IPv6 address and strip them

Assume [] surround an IPv6 address and strip them

Browsers such as Firefox, Chromium, and Safari prefer bare IPv6 addresses in
CNs. They generate confusing errors when they see bracketed CNs. For example:

You attempted to reach [2001:470:1:18::120], but instead you actually reached
a server identifying itself as [2001:470:1:18::120]. Chromium can say for sure
that you reached [2001:470:1:18::120], but cannot verify that that is the same
site as [2001:470:1:18::120] which you intended to reach.