Merge pull request #4114 from Maaarcocr/patch-1

Check for nullable result value to avoid errors on unsubscription

javascript_client/src/subscriptions/ActionCableLink.ts

@@ -46,7 +46,7 @@ class ActionCableLink extends ApolloLink {
           )
         },
         received: function(payload) {
-          if (payload.result.data || payload.result.errors) {
+          if (payload?.result?.data || payload?.result?.errors) {
             observer.next(payload.result)
           }