Fix ContentPackConfigLoader so that the default values from config schema are still used and applied even if a pack doesn't contain a config file.
Fix ContentPackConfigLoader so that the default values from config
schema are still used and applied even if a pack doesn't contain a
config file.

nzlosh/st2,nzlosh/st2,Plexxi/st2,tonybaloney/st2,nzlosh/st2,StackStorm/st2,nzlosh/st2,Plexxi/st2,Plexxi/st2,StackStorm/st2,StackStorm/st2,Plexxi/st2,StackStorm/st2,tonybaloney/st2,tonybaloney/st2