Pylint for job_obsevent_dispatcher.py

Pylint for job_obsevent_dispatcher.py

Use pylint disable-msg=E1101 since sys.setdefaultencoding is special
and gets removed from the namespace.

In dict, `in` is not just pythonic but also in performance than `has_key`, e.g.:

$ python -mtimeit -s'd=dict.fromkeys(range(99))' '12 in d'
10000000 loops, best of 3: 0.0492 usec per loop
$ python -mtimeit -s'd=dict.fromkeys(range(99))' 'd.has_key(12)'
10000000 loops, best of 3: 0.0937 usec per loop

In addition, has_key() is deprecated in favor of key in d:

http://docs.python.org/2/library/stdtypes.html#dict.has_key

Change-Id: Ic8b087d99ff8557c0c7f6a786478c037be03f0cf
Signed-off-by: Lingchaox Xin <lingchaox.xin@intel.com>