[nationalgeographic] skip download for national geographic channel tests(closes #9991)

youtube_dl/extractor/nationalgeographic.py

@@ -79,6 +79,10 @@ class NationalGeographicChannelIE(ThePlatformIE):
                 'upload_date': '20160322',
                 'uploader': 'NEWA-FNG-NGTV',
             },
+            'params': {
+                # m3u8 download
+                'skip_download': True,
+            },
             'add_ie': ['ThePlatform'],
         },
         {
@@ -93,6 +97,10 @@ class NationalGeographicChannelIE(ThePlatformIE):
                 'upload_date': '20160330',
                 'uploader': 'NEWA-FNG-NGTV',
             },
+            'params': {
+                # m3u8 download
+                'skip_download': True,
+            },
             'add_ie': ['ThePlatform'],
         },
     ]