Ntpd

Сorrected work with centos. [#516](https://github.com/Eugeny/ajenti/issues/516)
ср.

    >>> def imethod(self, kwarg=None):
    ...     print self, kwarg
    ... 
    >>> import types
    >>> a.m2 = types.MethodType(imethod, a)
    >>> a.m2('asd')
    <__main__.A object at 0x7f872d8c7b50> asd