deduplicate authorities events

pallets/authority-members/src/lib.rs

@@ -575,18 +575,25 @@ impl<T: Config> pallet_session::SessionManager<T::ValidatorId> for Pallet<T> {
             return None;
         }
 
+        // -- handle incoming members
+        // callback when smith is incoming
         for member_id in members_ids_to_add.iter() {
             T::OnIncomingMember::on_incoming_member(*member_id);
+        }
+        // a single event with all authorities
         Self::deposit_event(Event::IncomingAuthorities {
             members: members_ids_to_add.clone(),
         });
-        }
+
+        // -- handle outgoing members
+        // callback when smith is outgoing
         for member_id in members_ids_to_del.iter() {
             T::OnOutgoingMember::on_outgoing_member(*member_id);
+        }
+        // a single event with all authorities
         Self::deposit_event(Event::OutgoingAuthorities {
             members: members_ids_to_del.clone(),
         });
-        }
 
         // updates the list of OnlineAuthorities and returns the list of their key
         Some(