add cache option

[Dong-Gao]

add cache option the default/missing cache value is false, which means it does not store response body on local disk, so no longer worry about too much disk usage; when cache is false, the webinterface is forced to disable

If you want to keep local cache, e.g the webInterface is needed, you can also set cache value to true

const options = {
  port: 8001,
  cache: false
};

const proxyServer = new AnyProxy.ProxyServer(options);

[CLAassistant]

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