freifunk-p2pblock / luci-app-p2pblock: mark BROKEN

Mark freifunk-p2pblock and luci-app-p2pblock BROKEN
as p2pblock needs layer7 support in iptables, which
was removed in early 2015 from iptables-mod-filter:
https://dev.openwrt.org/changeset/45423
https://dev.openwrt.org/changeset/45424

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>