[WordPress] Limit feed to 20 items

[ORelio]

I encountered a WordPress site having all its articles from the beginning in its feed, which meant hundreds of entries.
Fetching all the articles is time consuming, so the feed failed to load in RSS-Bridge because of a script timeout.
This PR adds a limit of 20 items in WordPress bridge to keep load times reasonable and avoid hammering the target site.
Extra items are kept unexpanded so they will still be present in the feed.

[em92]

Hi, @ORelio! I suggest to discard those 20+ items instead of leaving unexpanded. In feed readers like Tiny Tiny RSS old items will be rewrited to unexpanded, if we leave like this.

[ORelio]

Sure, done. Now the feed is truncated to 20 items.

[VerifiedJoseph]

You can use collectExpandableDatas() to limit number of items returned, its simpler than your current method.

try{
	$this->collectExpandableDatas($this->getURI() . '/feed/atom/', 20);
} catch (Exception $e) {
	$this->collectExpandableDatas($this->getURI() . '/?feed=atom', 20);
}

[ORelio]

Oh nice, thanks @VerifiedJoseph for the tip! Done.

[em92]

Thanks @ORelio and @VerifiedJoseph !