Duplicate link detection ignores anchor

Zulip links to specific discussions put lots of information in the anchors, and the only thing before the anchor is the top-level domain (such as rust-lang.zulipchat.com). Discourse seems to ignore the anchor when doing duplicate link detection, which results in messages like this:

It looks like your link to rust-lang.zulipchat.com was already posted in the topic by @josh in a reply on Jun 3, '20 – are you sure you want to post it again?

That link has a different anchor, so it shouldn’t count as a duplicate.