firewall: depend on kmod-nf-conntrack6

Firewall rules don't work as intended without conntrack support. The recent
cleanup removed the kmod-nf-conntrack6 dependency from the iptables
modules; add it to the firewall package instead.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>

package/network/config/firewall/Makefile

@@ -9,7 +9,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=firewall
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL=$(PROJECT_GIT)/project/firewall3.git
@@ -28,7 +28,7 @@ define Package/firewall
   SECTION:=net
   CATEGORY:=Base system
   TITLE:=OpenWrt C Firewall
-  DEPENDS:=+libubox +libubus +libuci +libip4tc +IPV6:libip6tc +libxtables +kmod-ipt-core +kmod-ipt-conntrack +kmod-ipt-nat
+  DEPENDS:=+libubox +libubus +libuci +libip4tc +IPV6:libip6tc +libxtables +kmod-ipt-core +kmod-ipt-conntrack +IPV6:kmod-nf-conntrack6 +kmod-ipt-nat
 endef
 
 define Package/firewall/description