Add default fallback values for creator_data

youtube_dl/extractor/xvideos.py

@@ -149,6 +149,9 @@ class XVideosIE(InfoExtractor):
         tags = self._search_regex(r'<meta name="keywords" content="xvideos,xvideos\.com, x videos,x video,porn,video,videos,(?P<tag>.+?)"', webpage, 'tags', group='tag', default='').split(',')
 
         creator_data = re.findall(r'<a href="(?P<creator_url>.+?)" class="btn btn-default label main uploader-tag hover-name"><span class="name">(?P<creator>.+?)<', webpage)
+        creator = ''
+        uploader_url = ''
+        if creator_data is not None:
             creator = creator_data[0][1]
             uploader_url = creator_data[0][0]