utils: Free list of object config files

By not freeing them, the list of config files doubles for each reload.
As naemon very diligently verifies that no object is defined twice, this
meant that reloads always failed.

Change-Id: Ibdf2720efb38e80acbad9c8c9dbde897763d8a15
Signed-off-by: Robin Sonefors <robin.sonefors@op5.com>