[config] Ignore should have a default

[Stefano Rivera]

ERROR:scripts.ibid-plugin:Exception occured in Ignore processor of core plugin
Traceback (most recent call last):
  File "scripts/ibid-plugin", line 122, in <module>
    processor.process(event)
  File "/home/stefanor/svk/projects/ibid/add-config-400986/ibid/plugins/__init__.py", line 56, in process
    method(event)
  File "/home/stefanor/svk/projects/ibid/add-config-400986/ibid/plugins/core.py", line 62, in handle_ignore
    for who in ibid.config.plugins[self.name]['ignore']:
  File "/home/stefanor/svk/projects/ibid/add-config-400986/ibid/../lib/configobj.py", line 580, in __getitem__
    val = dict.__getitem__(self, key)
KeyError: 'ignore'

[Michael Gorven (mgorven)]

 status inprogress
 assignee mgorven

[Michael Gorven (mgorven)]

 status fixreleased