2360 Fixed Able to update user with Invalid Role

Change-Id: Id0a5f85ef101e2e04e52f36f775aa3c30a19ba2a
Signed-off-by: jegan <jegan.s@tataelxsi.co.in>
diff --git a/osm_nbi/admin_topics.py b/osm_nbi/admin_topics.py
index a98e2ff..e560887 100644
--- a/osm_nbi/admin_topics.py
+++ b/osm_nbi/admin_topics.py
@@ -1149,6 +1149,21 @@
                             mapping["role_name"],
                         ):
                             mappings_to_remove.append(mapping)
+                if len(original_mapping) == 0 or len(mappings_to_remove) == 0:
+                    pid = self.auth.get_project(to_remove["project"])["_id"]
+                    if to_remove.get("role"):
+                        rid = self.auth.get_role(to_remove["role"])["_id"]
+
+                        raise AuthconnNotFoundException(
+                            "User is not mapped with project '{}' or role '{}'".format(
+                                to_remove["project"], to_remove["role"]
+                            )
+                        )
+                    raise AuthconnNotFoundException(
+                        "User is not mapped with project '{}'".format(
+                            to_remove["project"]
+                        )
+                    )
 
             # add
             for to_add in indata.get("add_project_role_mappings", ()):