Update submodules: plugins (new commits)

plugins:
    87cd3e2 Chris Smith <chris@dmdirc.com>
            Desingleton DccCommandParser.

            Can't see why it was a singleton, really.

            Gerrit: http://gerrit.dmdirc.com/2838

Change-Id: I853426b1b1f13d1032195f4bbccd971fad7f001c

modules/plugins

@@ -1 +1 @@
-Subproject commit 37d3c188587bcde8f146dd466d0837e8cfea1827
+Subproject commit 87cd3e23b6d60988409fb1b749bb12614153af8e