luci-proto-vti: add missing license information

Signed-off-by: Florian Eckert <fe@dev.tdt.de>

protocols/luci-proto-vti/Makefile

@@ -8,6 +8,7 @@ LUCI_TITLE:=Support for VTI interfaces
 LUCI_DEPENDS:=+vti
 
 PKG_MAINTAINER:=Jaymin Patel <jem.patel@gmail.com>
+PKG_LICENSE:=Apache-2.0
 
 include ../../luci.mk