[nowvideo] Fix key extraction

Extract it from the embed page

youtube_dl/extractor/nowvideo.py

@@ -20,7 +20,10 @@ class NowVideoIE(InfoExtractor):
 
         video_id = mobj.group('id')
         webpage_url = 'http://www.nowvideo.ch/video/' + video_id
+        embed_url = 'http://embed.nowvideo.ch/embed.php?v=' + video_id
         webpage = self._download_webpage(webpage_url, video_id)
+        embed_page = self._download_webpage(embed_url, video_id,
+            u'Downloading embed page')
 
         self.report_extraction(video_id)
 
@@ -28,7 +31,7 @@ class NowVideoIE(InfoExtractor):
             webpage, u'video title')
 
         video_key = self._search_regex(r'var fkzd="(.*)";',
-            webpage, u'video key')
+            embed_page, u'video key')
 
         api_call = "http://www.nowvideo.ch/api/player.api.php?file={0}&numOfErrors=0&cid=1&key={1}".format(video_id, video_key)
         api_response = self._download_webpage(api_call, video_id,