let sendToConfigHost body use the parameter "env" to keep align with its signature and other methods

Hello,

This change wants to avoid breaking an assumption.

Also note that Indexer#doIndexerExecution(...) doesn't have a parameter "env", which is different from #prepareIndexer(...) and #sendConfigToHost(...)

I guess that you want the non-static methods to have the parameter "env", while the static method main() can access RuntimeEnvironment.getInstance() directly. Is it right?

Thanks