remove addon: tcpdump

does not compile. libpcap broken?

.../toolchain/bin/x86_64-openelec-linux-gnu-ranlib libnetdissect.a

/tmp/cc3bJtYs.ltrans21.ltrans.o:cc3bJtYs.ltrans21.o:function del_mon_if: error: undefined reference to 'nlmsg_alloc'
/tmp/cc3bJtYs.ltrans21.ltrans.o:cc3bJtYs.ltrans21.o:function del_mon_if: error: undefined reference to 'genl_family_get_id'
/tmp/cc3bJtYs.ltrans21.ltrans.o:cc3bJtYs.ltrans21.o:function del_mon_if: error: undefined reference to 'genlmsg_put'
/tmp/cc3bJtYs.ltrans21.ltrans.o:cc3bJtYs.ltrans21.o:function del_mon_if: error: undefined reference to 'nla_put'
/tmp/cc3bJtYs.ltrans21.ltrans.o:cc3bJtYs.ltrans21.o:function del_mon_if: error: undefined reference to 'nl_send_auto_complete'
/tmp/cc3bJtYs.ltrans21.ltrans.o:cc3bJtYs.ltrans21.o:function del_mon_if: error: undefined reference to 'nl_geterror'
/tmp/cc3bJtYs.ltrans21.ltrans.o:cc3bJtYs.ltrans21.o:function del_mon_if: error: undefined reference to 'nlmsg_free'
/tmp/cc3bJtYs.ltrans21.ltrans.o:cc3bJtYs.ltrans21.o:function del_mon_if: error: undefined reference to 'nl_wait_for_ack'