fix: tests setting http last modified

Signed-off-by: Ben Vidulich <ben@vidulich.nz>

tests/Unit/Fetcher/FeedFetcherTest.php

@@ -347,7 +347,7 @@ public function testFetchAccount()
             false,
             'account@email.com',
             'F9sEU*Rt%:KFK8HMHT&',
-            $this->modified->format(DateTime::RSS)
+            null
         );
 
         $this->assertEquals([$feed, [$item]], $result);
@@ -697,9 +697,6 @@ private function createFeed($lang = 'de-DE', $url = null)
         $this->feed_mock->expects($this->exactly(1))
             ->method('getLink')
             ->will($this->returnValue($this->feed_link));
-        $this->feed_mock->expects($this->exactly(2))
-            ->method('getLastModified')
-            ->will($this->returnValue($this->modified));
         $this->feed_mock->expects($this->exactly(1))
             ->method('getLanguage')
             ->will($this->returnValue($lang));
@@ -710,7 +707,6 @@ private function createFeed($lang = 'de-DE', $url = null)
         $feed->setLink($this->feed_link);
         $feed->setLocation($this->location);
         $feed->setUrl($url);
-        $feed->setHttpLastModified((new DateTime('@3'))->format(DateTime::RSS));
         $feed->setAdded($this->time);
 
         $feed->setFaviconLink('http://anon.google.com');