[theoperaplatform] Rename, fix _VALID_URL and fix test

youtube_dl/extractor/arte.py

@@ -410,13 +410,13 @@ class ArteTVEmbedIE(ArteTVPlus7IE):
         return self._extract_from_json_url(json_url, video_id, lang)
 
 
-class ArteTVOperaPlatformIE(ArteTVPlus7IE):
+class TheOperaPlatformIE(ArteTVPlus7IE):
-    IE_NAME = 'arte.tv:operaplatform'
+    IE_NAME = 'theoperaplatform'
-    _VALID_URL = r'https?://www.theoperaplatform.eu/(?P<lang>fr|de|en|es)/(?P<id>[^/?#&]+)'
+    _VALID_URL = r'https?://(?:www\.)?theoperaplatform\.eu/(?P<lang>fr|de|en|es)/(?P<id>[^/?#&]+)'
 
     _TESTS = [{
         'url': 'http://www.theoperaplatform.eu/de/opera/verdi-otello',
-        'md5': '80f5d3fc97957b5dbfc1ddfde93b8098',
+        'md5': '970655901fa2e82e04c00b955e9afe7b',
         'info_dict': {
             'id': '060338-009-A',
             'ext': 'mp4',