Update register.sh

register.sh

@@ -3,7 +3,7 @@
 
 TOKEN=$1
 if [ -z "${TOKEN}" ] ; then
-    echo "Usage: .\register.ps1 TOKEN"
+    echo "Usage: .\register.sh TOKEN"
     echo "You can get the registration token from http://127.0.0.1/admin/runners"
     exit 1
 fi
@@ -18,4 +18,4 @@ if [ ! -z "${DOCKER_ID}" ]; then
 fi
 
 echo "Done ."
-exit 0
+exit 0