diffutils: fix gets() with glibc-2.17 in gnulib.

srcpkgs/diffutils/template

@@ -15,3 +15,7 @@ long_desc="
  features are a superset of the Unix features and they are significantly
  faster. Cmp has been moved into this package from the GNU textutils package.
  These programs are usually used for creating patch files."
+
+pre_configure() {
+	sed -i -e '/gets is a/d' lib/stdio.in.h
+}