usb canary only installs once

src/freedombone-utils-setup

@@ -552,8 +552,14 @@ function disable_null_passwords {
 }
 
 function create_usb_canary {
+    if [[ $(is_completed $FUNCNAME) == "1" ]]; then
+        return
+    fi
+
     echo "ACTION==\"add\", KERNEL==\"sd*[!0-9]\", RUN+=\"/usr/local/bin/${PROJECT_NAME}-usb-canary\"" > /etc/udev/rules.d/00-usb-canary.rules
     udevadm control --reload-rules
+
+    mark_completed $FUNCNAME
 }
 
 function setup_firewall {