Update submodules: plugins (new commits)

plugins:
    1b3a531 Greg Holmes <greg@dmdirc.com>
            Remove some warnings

            Gerrit: http://gerrit.dmdirc.com/3166

Change-Id: I7195b80adffd8d9e29602e4cff3adf8868d0ba29
Report warnings as deprecations + non-deprecations

Change-Id: I0be37863d3478705ded21275829ee9fef0b6d613
Reviewed-on: http://gerrit.dmdirc.com/3165
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Add IconManager to plugin initialiser.

Tidy uiattachdialog.

Change-Id: Ib19578e5246ef5d24140b112076bb44e421d8069
Reviewed-on: http://gerrit.dmdirc.com/3162
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Chris Smith <chris@dmdirc.com>