package/nanomsg: fix legal-info failure

After version bump, the sha256 has been updated
while the COPYING file remains unchanged.

Fixes:
 - http://autobuild.buildroot.net/results/ec1cb0216ebedc5c7bd2c8719460db28b666a24f/

Signed-off-by: Pierre-Jean Texier <pjtexier@koncepto.io>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/nanomsg/nanomsg.hash

@@ -2,4 +2,4 @@
 sha256 218b31ae1534ab897cb5c419973603de9ca1a5f54df2e724ab4a188eb416df5a  nanomsg-1.1.5.tar.gz
 
 # Hash for license file:
-sha256 9755181e27175cb3510b4da8629caa406fb355a19aa8e7d55f06bf8ab33323c4  COPYING
+sha256 4e51f6a04312ea7c5f4f0e92d91b6415c1eeb09bdaf86a6fd11d93499457c07a  COPYING