Disable update cluster operation in NBI

Change-Id: I463ee7c3007436d3220c7f326a566933a43ead8d
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/osm_nbi/nbi.py b/osm_nbi/nbi.py
index 1d8fa26..4e7e8ee 100644
--- a/osm_nbi/nbi.py
+++ b/osm_nbi/nbi.py
@@ -2052,7 +2052,7 @@
                         engine_session, engine_topic, _id, indata, kwargs
                     )
                     outdata = {"op_id": op_id}
-                elif topic == "clusters" and item in ("upgrade", "scale", "update"):
+                elif topic == "clusters" and item in ("upgrade", "scale"):
                     op_id = self.engine.update_cluster(
                         engine_session, engine_topic, _id, item, indata
                     )