Update submodules: util (new commits)

util:
    5b7f3a9 Chris Smith <chris@dmdirc.com>
            Allow ConfigFile to work on Paths.

            Apply a bunch of style fixes.

            Gerrit: http://gerrit.dmdirc.com/4000

Change-Id: I26514c6518d6c329fd2da7e51cbfbd5529d59b23