Update submodules: plugins (new commits)

plugins:
    d7acaa3 Chris Smith <chris@dmdirc.com>
            Don't expose servers.

            Gerrit: http://gerrit.dmdirc.com/3869

Change-Id: I0629848c6886dcf91bda88196aafdbceff177bfe
Don't expose servers.

Change-Id: I5db4e866f20ca7e8d4c1ba596ef6248755f4d2ec
Depends-On: I58e485b06887b1215b4d4cba7f2244404a7b81aa
Reviewed-on: http://gerrit.dmdirc.com/3870
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Automatic-Compile: DMDirc Build Manager