Revert "Use ffprobe to try to get file extension"

This reverts commit 1caef9097b.

redditbot.py

@@ -230,22 +230,6 @@ async def main():
         proc = await asyncio.create_subprocess_exec('file', '--brief', '--extension', filename, stdout=asyncio.subprocess.PIPE)
         stdout, _ = await proc.communicate()
         ext = stdout.decode().strip().split('/', maxsplit=1)[0]
-        if not ext or ext == '???':
-            ffprobe_exists = any(True for i in os.environ.get('PATH', '').split(':') if os.path.exists(os.path.join(i, 'ffprobe')))
-            if ffprobe_exists:
-                proc = await asyncio.create_subprocess_exec('ffprobe', '-print_format', 'json', '-show_format', filename, stdout=asyncio.subprocess.PIPE)
-                stdout, _ = await proc.communicate()
-                format = json.loads(stdout).get('format')
-                if format:
-                    format_name = format.get('format_name')
-                    if format_name:
-                        proc = await asyncio.create_subprocess_exec('ffprobe', '-h', f'demuxer={format_name}', stdout=asyncio.subprocess.PIPE)
-                        stdout, _ = await proc.communicate()
-                        text = stdout.decode().split('\n', 2)
-                        if len(text) > 1:
-                            text = text[1].strip().rstrip('.')
-                            if text.startswith('Common extensions: '):
-                                ext = text[19:].split(',', 1)[0]
         if not ext or ext == '???':
             mimetype = await _get_file_mimetype(filename)
             ext = mimetypes.guess_extension(mimetype) or '.bin'