fix python 'class' snippet

Currently ``class`` snippet expands to this ( when args added to init):

```python
class MyClass(object):
    """Docstring for MyClass """

    def __init__(self, a, b):
        """@todo: to be defined1

        :param a: @todo
        :param b: @todo

        """ 2 
        self._a = a
        self._b = b
        

```
Which is wrong because of this part: ``""" 2 ``