collectd: use uname to get default Hostname

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

utils/collectd/files/collectd.init

@@ -189,7 +189,7 @@ process_config() {
 	config_get ReadThreads globals ReadThreads 2
 	printf "ReadThreads \"%s\"\n" "$ReadThreads" >> "$COLLECTD_CONF"
 
-	config_get Hostname globals Hostname "$(hostname)"
+	config_get Hostname globals Hostname "$(uname -n)"
 	printf "Hostname \"%s\"\n" "$Hostname" >> "$COLLECTD_CONF"
 
 	printf "\n" >> "$COLLECTD_CONF"