package/libtool: add license hash

Signed-off-by: Samuel Martin <s.martin49@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/libtool/libtool.hash

@@ -1,2 +1,4 @@
 # Locally calculated after checking pgp signature
 sha256	7c87a8c2c8c0fc9cd5019e402bed4292462d00a718a7cd5f11218153bf28b26f	libtool-2.4.6.tar.xz
+# License files, locally calculated
+sha256	8177f97513213526df2cf6184d8ff986c675afb514d4e68a404010521b880643	COPYING