Fixup sensehat to not use sudo if not needed

hardware/sensehat/package.json

@@ -1,6 +1,6 @@
 {
     "name"          : "node-red-node-pi-sense-hat",
-    "version"       : "0.0.17",
+    "version"       : "0.0.18",
     "description"   : "A Node-RED node to interact with a Raspberry Pi Sense HAT",
     "repository" : {
         "type":"git",

hardware/sensehat/sensehat

@@ -1,4 +1,14 @@
 #!/bin/bash
 
 BASEDIR=$(dirname $0)
-sudo python -u $BASEDIR/sensehat.py $@
+
+ID=$(id -u)
+
+# Avoid using sudo if we're already root
+SUDO=sudo
+if [ $ID -eq 0 ]
+then
+   SUDO=""
+fi
+
+$SUDO python -u $BASEDIR/sensehat.py $@