Update cmd.py

Author: eric-wieser

git/cmd.py

@@ -701,8 +701,7 @@ def __next__(self) -> bytes:
 
             return line
 
-        def next(self) -> bytes:
-            return next(self)
+        next = __next__
 
         def __del__(self) -> None:
             bytes_left = self._size - self._nbr