ipip: remove setting default firewall zone to wan

Same reasoning as in bdedb798150a58ad7ce3c4741f2f31df97e84c3f; don't set
default firewall zone to wan as the firewall zone for the ipip interface
can be configured in the firewall config or it makes it impossible not to
specify a firewall zone for the ipip interface.

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

package/network/config/ipip/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=ipip
 PKG_VERSION:=1
-PKG_RELEASE:=2
+PKG_RELEASE:=3
 PKG_LICENSE:=GPL-2.0
 
 include $(INCLUDE_DIR)/package.mk

package/network/config/ipip/files/ipip.sh

@@ -47,8 +47,6 @@ proto_ipip_setup() {
 		fi
 	}
 
-	[ -z "$zone" ] && zone="wan"
-
 	proto_init_update "ipip-$cfg" 1
 
 	proto_add_tunnel