remove mention of nonexistent `_margv` in macro

closes  #3476

IPython/core/macro.py

@@ -1,59 +1,57 b''
 """Support for interactive macros in IPython"""
 
 #*****************************************************************************
 #       Copyright (C) 2001-2005 Fernando Perez <[e-mail]>
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #*****************************************************************************
 
 import re
 
 from IPython.utils import py3compat
 from IPython.utils.encoding import DEFAULT_ENCODING
 
 coding_declaration = re.compile(r"#\s*coding[:=]\s*([-\w.]+)")
 
 class Macro(object):
     """Simple class to store the value of macros as strings.
 
     Macro is just a callable that executes a string of IPython
     input when called.
-    
-    Args to macro are available in _margv list if you need them.
     """
 
     def __init__(self,code):
         """store the macro value, as a single string which can be executed"""
         lines = []
         enc = None
         for line in code.splitlines():
             coding_match = coding_declaration.match(line)
             if coding_match:
                 enc = coding_match.group(1)
             else:
                 lines.append(line)
         code = "\n".join(lines)
         if isinstance(code, bytes):
             code = code.decode(enc or DEFAULT_ENCODING)
         self.value = code + '\n'
     
     def __str__(self):
         return py3compat.unicode_to_str(self.value)
     
     def __unicode__(self):
         return self.value
 
     def __repr__(self):
         return 'IPython.macro.Macro(%s)' % repr(self.value)
     
     def __getstate__(self):
         """ needed for safe pickling via %store """
         return {'value': self.value}
     
     def __add__(self, other):
         if isinstance(other, Macro):
             return Macro(self.value + other.value)
         elif isinstance(other, basestring):
             return Macro(self.value + other)
         raise TypeError