Fix hook script for Ironic

cleanup_ironic should not be started on "unstack" phase,
otherwise API service not restarted because auth cache
directory removed.

Change-Id: I3da86b9fb8c3ce1185aff05df0fa83cf259708f4
diff --git a/extras.d/50-ironic.sh b/extras.d/50-ironic.sh
index f68a146..9e61dc5 100644
--- a/extras.d/50-ironic.sh
+++ b/extras.d/50-ironic.sh
@@ -28,6 +28,9 @@
 
     if [[ "$1" == "unstack" ]]; then
         stop_ironic
+    fi
+
+    if [[ "$1" == "clean" ]]; then
         cleanup_ironic
     fi
 fi