network-manager: add upstream hash origin

The commit log in c511ca937d4 (network-manager: add hash file) claimed to fix
hash origin, but didn't actually do so.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/network-manager/network-manager.hash

@@ -1,2 +1,2 @@
-# Locally computed:
+# From http://ftp.gnome.org/pub/GNOME/sources/NetworkManager/1.0/NetworkManager-1.0.0.sha256sum
 sha256  3a66afec670c975edd9832e620b725a5f16ed267a1b9e1b2d51ef27250d85947  NetworkManager-1.0.0.tar.xz