Omit ambiguous .mpa (audio/mpeg on Windows)

Author: hugovk

Lib/test/test_mimetypes.py

@@ -295,7 +295,6 @@ def check_file_type():
                 ("audio/mpeg", ".mp2"),
                 ("audio/mpeg", ".mp3"),
                 ("video/mpeg", ".m1v"),
-                ("video/mpeg", ".mpa"),
                 ("video/mpeg", ".mpe"),
                 ("video/mpeg", ".mpeg"),
                 ("video/mpeg", ".mpg"),