package/iptables: need pkgconf-host to properly create configure script

Signed-off-by: Phil Sutter <phil@nwl.cc>

package/iptables/Makefile

@@ -10,7 +10,7 @@ PKG_HASH:=		52004c68021da9a599feed27f65defcfb22128f7da2c0531c0f75de0f479d3e0
 PKG_DESCR:=		netfilter firewalling software
 PKG_SECTION:=		net/firewall
 PKG_DEPENDS:=		libnetfilter_conntrack libmnl libnfnetlink
-PKG_BUILDDEP:=		libnetfilter_conntrack
+PKG_BUILDDEP:=		libnetfilter_conntrack pkgconf-host
 PKG_URL:=		http://www.netfilter.org/
 PKG_SITES:=		http://www.netfilter.org/projects/iptables/files/
 PKG_OPTS:=		dev