Remove the test to signature of lengths 43,43

It's already covered by the test for length 87

test/test_youtube_sig.py

@@ -13,11 +13,6 @@ from helper import FakeYDL
 sig = YoutubeIE(FakeYDL())._decrypt_signature
 
 class TestYoutubeSig(unittest.TestCase):
-    def test_43_43(self):
-        wrong = '5AEEAE0EC39677BC65FD9021CCD115F1F2DBD5A59E4.C0B243A3E2DED6769199AF3461781E75122AE135135'
-        right = '931EA22157E1871643FA9519676DED253A342B0C.4E95A5DBD2F1F511DCC1209DF56CB77693CE0EAE'
-        self.assertEqual(sig(wrong), right)
-
     def test_92(self):
         wrong = "F9F9B6E6FD47029957AB911A964CC20D95A181A5D37A2DBEFD67D403DB0E8BE4F4910053E4E8A79.0B70B.0B80B8"
         right = "69B6E6FD47029957AB911A9F4CC20D95A181A5D3.A2DBEFD67D403DB0E8BE4F4910053E4E8A7980B7"