Update submodules: plugins (new commits)

plugins:
    58056e7 Chris Smith <chris@dmdirc.com>
            Write information about deps in plugins.

            Write the build environment to a list section of the plugin
            meta-data. This should make it easier to figure out what
            on earth is going on when everything breaks.

            Gerrit: http://gerrit.dmdirc.com/4010

Change-Id: I15db391963e59bfc201aaa66c1ff903fce89a421