Fixing role attribution in Keystone

Corrects a bug in the init script that would not assign the role

Change-Id: I08e1f3a17b285faeccdd6d3b70f3ab6e1260310f
Signed-off-by: Eduardo Sousa <eduardo.sousa@canonical.com>
diff --git a/docker/Keystone/scripts/start.sh b/docker/Keystone/scripts/start.sh
index dafb23b..8dd61ad 100755
--- a/docker/Keystone/scripts/start.sh
+++ b/docker/Keystone/scripts/start.sh
@@ -119,7 +119,7 @@
 if [ -z $DB_EXISTS ] || [ -z $DB_NOT_EMPTY ]; then
     openstack user create --domain default --password "$SERVICE_PASSWORD" "$SERVICE_USERNAME"
     openstack project create --domain default --description "Service Project" "$SERVICE_PROJECT"
-    openstack role add --project "$SERVICE_PROJECT" --user "$SERVICE_USER" admin
+    openstack role add --project "$SERVICE_PROJECT" --user "$SERVICE_USERNAME" admin
     openstack role delete _member_
 fi