also use url in user agent

fetcher/feedfetcher.php

@@ -74,7 +74,9 @@ class FeedFetcher implements IFeedFetcher {
 		$simplePie = $this->simplePieFactory->getCore();
 		$simplePie->set_feed_url($url);
 		$simplePie->enable_cache(true);
-		$simplePie->set_useragent('ownCloud News/' . $this->appConfig->getConfig('version') . ' (+https://owncloud.org/; 1 subscriber)');
+		$simplePie->set_useragent('ownCloud News/' .
+				$this->appConfig->getConfig('version') .
+				' (+https://owncloud.org/; 1 subscriber; feed-url=' . $url . ')');
 		$simplePie->set_stupidly_fast(true);  // disable simple pie sanitation
 		                                      // we use htmlpurifier
 		$simplePie->set_timeout($this->fetchTimeout);

tests/unit/fetcher/FeedFetcherTest.php

@@ -199,7 +199,9 @@ class FeedFetcherTest extends \PHPUnit_Framework_TestCase {
 			->with($this->equalTo($this->cacheDuration));
 		$this->core->expects($this->once())
 			->method('set_useragent')
-			->with($this->equalTo('ownCloud News/3 (+https://owncloud.org/; 1 subscriber)'));
+			->with($this->equalTo(
+				'ownCloud News/3 (+https://owncloud.org/; 1 subscriber; ' .
+					'feed-url=http://tests)'));
 		$this->setExpectedException('\OCA\News\Fetcher\FetcherException');
 		$this->fetcher->fetch($this->url);
 	}