wic: fix pylint warning no-member

Fixed pylint warning:
Instance of 'ConfigMgr' has no 'create' member (no-member)

(From OE-Core rev: 41e319730cdd9c320ae4d855df7aaff6f1679aaf)

Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/lib/wic/conf.py

@@ -67,6 +67,7 @@ class ConfigMgr(object):
     def reset(self):
         self.__ksconf = None
         self.__siteconf = None
+        self.create = {}
 
         # initialize the values with defaults
         for sec, vals in self.DEFAULTS.iteritems():