linux postinstall: replace no longer working --output param

packaging/linux/postinstall

@@ -19,15 +19,15 @@ ensure_line "nav/NAV_Sub_CA.crt" "/etc/ca-certificates.conf"
 update-ca-certificates
 
 # Assert just _one_ logged-in user
-user_accounts=$(loginctl list-users --output json | jq '[.[] | select(.uid >= 1000)]')
-if echo "$user_accounts" | jq -e 'length != 1' > /dev/null; then
+user_accounts=$(loginctl list-users -j | jq '[.[] | select(.uid >= 1000)]')
+if echo "$user_accounts" | jq -e 'length != 1' >/dev/null; then
 	printf "\nMore than 1 user account logged in! naisdevice only permits _one_ user account!\n"
 	exit 1
 fi
 
 # Assert only whitelisted service accounts "logged in" (if logged in at all)
-service_accounts=$(loginctl list-users --output  json | jq -e '[.[] | select(.uid < 1000)]')
-if echo "$service_accounts" | jq -e 'length > 0' > /dev/null; then
+service_accounts=$(loginctl list-users -j | jq -e '[.[] | select(.uid < 1000)]')
+if echo "$service_accounts" | jq -e 'length > 0' >/dev/null; then
 	is_not_whitelisted=0
 
 	whitelisted_service_accounts="gdm,"