The CouchDB query for ignore sets needs to be nil-guarded, too.
An option to hide "ignored this URL" output.

Note that hidden entries still count against the maximum scrollback
buffer size.  This can in some cases lead to entries disappearing, e.g.
if you end up with > 512 ignores in a row.

However, I don't think it's worth making this behavior consistent at
this point in time.