[morningstar] Recognize urls that use 'videoCenter' (fixes #2729)

youtube_dl/extractor/morningstar.py

@@ -8,7 +8,7 @@ from .common import InfoExtractor
 
 class MorningstarIE(InfoExtractor):
     IE_DESC = 'morningstar.com'
-    _VALID_URL = r'https?://(?:www\.)?morningstar\.com/cover/videocenter\.aspx\?id=(?P<id>[0-9]+)'
+    _VALID_URL = r'https?://(?:www\.)?morningstar\.com/cover/video[cC]enter\.aspx\?id=(?P<id>[0-9]+)'
     _TEST = {
         'url': 'http://www.morningstar.com/cover/videocenter.aspx?id=615869',
         'md5': '6c0acface7a787aadc8391e4bbf7b0f5',