nftables: fix build in static scenarios

When linking against readline, it forgets to link against ncurses,
which is needed by readline. Fix this by passing LIBS="-lcurses" to
the configure script.

Fixes:

  http://autobuild.buildroot.org/results/98b/98b707ffdeeb1cda94b7c1019ef29cf5fd7db8bf/

Signed-off-by: Thomas Petazzoni <[email protected]>
Signed-off-by: Peter Korsgaard <[email protected]>

package/nftables/nftables.mk

@@ -12,6 +12,8 @@ NFTABLES_DEPENDENCIES = gmp libmnl libnftnl readline host-bison host-flex \
 NFTABLES_LICENSE = GPLv2
 NFTABLES_LICENSE_FILES = COPYING
 
-NFTABLES_CONF_ENV = ac_cv_prog_CONFIG_PDF=no
+NFTABLES_CONF_ENV = \
+	ac_cv_prog_CONFIG_PDF=no \
+	LIBS="-lncurses"
 
 $(eval $(autotools-package))