mosquitto: specify that hash is taken from upstream

Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/mosquitto/mosquitto.hash

@@ -1,3 +1,3 @@
-# Locally computed:
+# From http://www.eclipse.org/downloads/download.php?file=/mosquitto/source/mosquitto-1.4.12.tar.gz
 sha512  75e6105498869ab13265df7a0bea6052c014d59d0c0efb61162d8257d34c0153fce32130e84c28e99fd494f374949aac5e01c19f7439c2eea575b52ef1179c3c  mosquitto-1.4.12.tar.gz
 sha256  06abd1206e548ac2378dd96f5434cb3e40ed77cecb6a9c37fbabab0b0f1360e5  mosquitto-1.4.x_cve-2017-9868.patch