Update submodules: plugins (new commits)

plugins:
    62bc3e4 Greg Holmes <greg@dmdirc.com>
            PMD should disallow whitespace in name.

            Fixes-Issue: CLIENT-468
            Gerrit: http://gerrit.dmdirc.com/3299

Change-Id: I1682bbec27cd409cc008875fd53e3ae34097c68e