vsftpd: add version check override

Skip version checks as none of the executables seem to report their
versions.

Signed-off-by: George Sapkin <george@sapk.in>
(cherry picked from commit 12cb2ccffd)
Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>

net/vsftpd/test-version.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+
+# shellcheck shell=busybox
+
+case "$PKG_NAME" in
+vsftpd|vsftpd-tls)
+	exit 0
+	;;
+
+*)
+	echo "Untested package: $PKG_NAME" >&2
+	exit 1
+	;;
+esac