[test:youtube_signature] Add `tce` test case

Authored by: bashonly

test/test_youtube_signature.py

@@ -262,6 +262,10 @@ _NSIG_TESTS = [
         'https://www.youtube.com/s/player/4fcd6e4a/player_ias.vflset/en_US/base.js',
         'o_L251jm8yhZkWtBW', 'lXoxI3XvToqn6A',
     ),
+    (
+        'https://www.youtube.com/s/player/4fcd6e4a/player_ias_tce.vflset/en_US/base.js',
+        'o_L251jm8yhZkWtBW', 'lXoxI3XvToqn6A',
+    ),
     (
         'https://www.youtube.com/s/player/20830619/tv-player-ias.vflset/tv-player-ias.js',
         'ir9-V6cdbCiyKxhr', '9YE85kNjZiS4',