olsrd: add iptables as dependency

Firewall4 will not ship iptables as default. However, we need iptables for
installing smart-gw-rules.

Instead of using the original iptables, we can also use iptables-nft:
  ... iptables-nft parses the iptables syntax on command line, creates
  appropriate nftables commands, packs them into netlink messages and
  submits them to kernel.
  https://www.redhat.com/en/blog/using-iptables-nft-hybrid-linux-firewall

Since, commit 795e7155cbe3 ("iptables: rename to ip(6)tables-legacy,
add PROVIDES") it is enough to include iptables as dependency to install
iptables-nft [0]. iptables-nft also PROVIDES iptables.

Fixes: openwrt#731 ("Certain upstream switch to firewall4 aka nftables instead
of iptables")

- [0] https://git.openwrt.org/?p=openwrt/openwrt.git;a=commit;h=795e7155cbe3e78669f6821bf7aecb7c4e1e1afbv

Signed-off-by: Nick Hainke <[email protected]>

olsrd/Makefile

@@ -34,7 +34,7 @@ endef
 define Package/olsrd
   $(call Package/olsrd/template)
   MENU:=1
-  DEPENDS:=+libpthread +libubus
+  DEPENDS:=+libpthread +libubus +iptables +ip6tables
 endef
 
 define Package/olsrd/conffiles