[soundcloud] Support URLs with a slash at the end (Fixes #1104)

youtube_dl/extractor/soundcloud.py

@@ -19,7 +19,7 @@ class SoundcloudIE(InfoExtractor):
        of the stream token and uid
      """
 
-    _VALID_URL = r'^(?:https?://)?(?:www\.)?soundcloud\.com/([\w\d-]+)/([\w\d-]+)(?:[?].*)?$'
+    _VALID_URL = r'^(?:https?://)?(?:www\.)?soundcloud\.com/([\w\d-]+)/([\w\d-]+)/?(?:[?].*)?$'
     IE_NAME = u'soundcloud'
     _TEST = {
         u'url': u'http://soundcloud.com/ethmusic/lostin-powers-she-so-heavy',