message: fix getV2rayNNodes undefined error
  add  `getV2rayNNodes` function to template engine context.
diff: @@ -24,6 +24,7 @@ import {
  getDownloadUrl,
  getNodeNames,
  getQuantumultNodes,
  + getV2rayNNodes,
  getQuantumultXNodes,
  getShadowsocksNodes,
  getShadowsocksNodesJSON,
  @@ -252,6 +253,7 @@ export async function generate(
  getShadowsocksNodesJSON,
  getShadowsocksrNodes,
  getQuantumultNodes,
  + getV2rayNNodes,
  getQuantumultXNodes,
  getMellowNodes,
  usFilter,
  