message: [Doc] Document removal of p2p alert system
diff: @@ -98,6 +98,8 @@ Detailed release notes follow. This overview includes changes that affect behavi
  ### P2P Protocol and Network Code
  +The p2p alert system has been removed in [#1372](https://github.com/PIVX-Project/PIVX/pull/1372) and the 'alert' message is no longer supported.
  +
  ### GUI
  ### RPC/REST
  