vti: 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 vti interface
can be configured in the firewall config or it makes it impossible not to
specify a firewall zone for the vti interface.

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

package/network/config/vti/Makefile

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

package/network/config/vti/files/vti.sh

@@ -16,8 +16,6 @@ vti_generic_setup() {
 	local mtu zone ikey
 	json_get_vars mtu zone ikey okey
 
-	[ -z "$zone" ] && zone="wan"
-
 	proto_init_update "$link" 1
 
 	proto_add_tunnel