iptables: make mod depend on libxtables

'iptables-mod-' can be used directly by firewall3, by
iptables and by iptables-nft. They are not linked to
iptables but to libxtables, so fix the dependencies to allow
to remove iptables(-legacy)

Signed-off-by: Etienne Champetier <champetier.etienne@gmail.com>

package/network/utils/iptables/Makefile

@@ -41,7 +41,7 @@ endef
 
 define Package/iptables/Module
 $(call Package/iptables/Default)
-  DEPENDS:=+iptables $(1)
+  DEPENDS:=+libxtables $(1)
 endef
 
 define Package/iptables
@@ -457,7 +457,6 @@ $(call Package/iptables/Default)
   DEPENDS:=@IPV6 +kmod-ip6tables +iptables
   CATEGORY:=Network
   TITLE:=IPv6 firewall administration tool
-  MENU:=1
   ALTERNATIVES:=\
     200:/usr/sbin/ip6tables:/usr/sbin/xtables-legacy-multi \
     200:/usr/sbin/ip6tables-restore:/usr/sbin/xtables-legacy-multi \
@@ -485,7 +484,7 @@ endef
 
 define Package/ip6tables-extra
 $(call Package/iptables/Default)
-  DEPENDS:=ip6tables +kmod-ip6tables-extra
+  DEPENDS:=+libxtables +kmod-ip6tables-extra
   TITLE:=IPv6 header matching modules
 endef
 
@@ -495,7 +494,7 @@ endef
 
 define Package/ip6tables-mod-nat
 $(call Package/iptables/Default)
-  DEPENDS:=ip6tables +kmod-ipt-nat6
+  DEPENDS:=+libxtables +kmod-ipt-nat6
   TITLE:=IPv6 NAT extensions
 endef