Nested u-url gets picked up as source in rss feed

[aciccarello]

I noticed strange behavior on webmention sending based on my atom feed where one of the targets was getting picked up as the source.

I debugged the code and realized a u-url inside of an h-cite of the post I was replying to was getting picked up as the permalink. It seems like links.js picks up the first u-url which in my case doesn't appear for the post in the feed.

wm/lib/links.js

Lines 16 to 19 in f61809c

	let permalink = resolve(
	baseHref,
	$$.find('.u-url').attr('href') || element.link || ''
	);

I was able to resolve the issue by stripping all u-url from the feed, which triggers a fallback to the feed element url, but simply looking for any u-url seems too simple.