make sure OS update does not prompt for choices

Author: wiedehopf

src/modules/adsb-feeder/filesystem/root/opt/adsb/scripts/update-os

@@ -8,7 +8,7 @@ if [ -x /boot/dietpi/dietpi-update ] ; then
     G_INTERACTIVE=0 CONFIG_CHECK_APT_UPDATES=2 /boot/dietpi/dietpi-update 1
 else
     apt update
-    apt upgrade -y
+    DEBIAN_FRONTEND=noninteractive apt upgrade -y
 fi
 
 # restart important services if not running for some reason