Remove dependeny on iptables-mod-filter from sqm-scripts
As Hnyman noted in https://github.com/dtaht/ceropackages-3.10/issues/13
we carry a few unnecessary dependecies in sqm-scripts, so remove one of
them (iptables-mod-filter) as we neither use it nor plan to use it.
Signed-off-by: Sebastian Moeller <moeller0@gmx.de>