netcat-openbsd: fix license typo

Signed-off-by: Jerzy Grzegorek <jerzy.grzegorek@trzebnica.net>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/netcat-openbsd/netcat-openbsd.mk

@@ -7,7 +7,7 @@
 NETCAT_OPENBSD_VERSION = debian/1.105-7
 NETCAT_OPENBSD_SITE = git://anonscm.debian.org/collab-maint/netcat-openbsd
 NETCAT_OPENBSD_LICENSE = BSD-3c
-NETCAT_OPENBSD_LICENSE_FILE = debian/copyright
+NETCAT_OPENBSD_LICENSE_FILES = debian/copyright
 NETCAT_OPENBSD_DEPENDENCIES = host-pkgconf libbsd
 
 # Ensure Busybox gets built/installed before, so that this package