libnetfilter_queue: does not build without IPv6 support

Fixes the following build failure:

extra/checksum.c:16:25: fatal error: netinet/ip6.h: No such file or directory
compilation terminated.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/libnetfilter_queue/Config.in

@@ -1,6 +1,7 @@
 config BR2_PACKAGE_LIBNETFILTER_QUEUE
 	bool "libnetfilter_queue"
 	depends on BR2_LARGEFILE
+	depends on BR2_INET_IPV6
 	select BR2_PACKAGE_LIBNFNETLINK
 	select BR2_PACKAGE_LIBMNL
 	help
@@ -10,5 +11,5 @@ config BR2_PACKAGE_LIBNETFILTER_QUEUE
 
 	  http://www.netfilter.org/projects/libnetfilter_queue/
 
-comment "libnetfilter_queue requires a toolchain with LARGEFILE support"
-	depends on !BR2_LARGEFILE
+comment "libnetfilter_queue requires a toolchain with LARGEFILE and IPv6 support"
+	depends on !BR2_LARGEFILE && !BR2_INET_IPV6