[ANN] nFlow 7.2.4 released

[nflow-users]

Hello all,

nFlow 7.2.4 was released on February 25, 2021.

https://github.com/NitorCreations/nflow/releases/tag/7.2.4

**Highlights**
- Support disabling `CronWorkflow`s.

**Details**
- `nflow-engine`
  - Add `disabled` state (type `manual`) to `CronWorkflow` to support disabling the work. By default there is no state method for the `disabled` state, but it can added in your workflow definition that extends `CronWorkflow` to execute custom logic when the workflow enters the `disabled` state.
- `nflow-rest-api-common` and `nflow-rest-api-spring-web`
  - Fix exception to HTTP status conversion issue when using Netty