message: Fix undefined error after deleting an activity
diff: -import { FLOGO_TASK_TYPE } from '@flogo/core/constants';
  import { select, Store } from '@ngrx/store';
  import { isEqual } from 'lodash';
  import { Observable } from 'rxjs';
  @@ -28,6 +27,10 @@ export function getChanges(flowState: FlowState, taskId, changedInputs) {
  items = flowState.errorItems;
  }
  const task = items[taskId] as ItemActivityTask;
  + if (!task) {
  + // update is not applicable anymore because task was deleted
  + return null;
  + }
  changedInputs = changedInputs || {};
  if (isEqual(changedInputs, task.input)) {
  return null;
  