Update submodules: plugins (new commits)

plugins:
    490f027 Greg Holmes <greg@dmdirc.com>
            EventBus logging for FreeDesktop notifications plugin.

            Gerrit: http://gerrit.dmdirc.com/3667

    a32eced Greg Holmes <greg@dmdirc.com>
            EventBus logging for exec plugin.

            Gerrit: http://gerrit.dmdirc.com/3666

Change-Id: I0d0824530554b4ba9893ffca5cc2da5cc1b0b727

modules/plugins

@@ -1 +1 @@
-Subproject commit e2b1419602b9599aead1fe5168d850b54ea358b5
+Subproject commit 490f0272006135c6579cec41895d994c9663b4bc