Update submodules: util (new commits)

util:
    18d85e6 Chris Smith <chris@dmdirc.com>
            Tidying

            Gerrit: http://gerrit.dmdirc.com/2806

Change-Id: If152c628b5e88a0affc2dcc84619fea331c9102e

modules/util

@@ -1 +1 @@
-Subproject commit 162c641385730fd25355e58d74e56cc3176eb746
+Subproject commit 18d85e6a10be288b31463ed5de9e9cffc80cdc7b