Wallet RPC guide: Correct empty subaddr_indices not defaulting to 0
This correct the wrong statement about subaddr_indices defaulting to 0.
This also updates the guide for outdated version on untranslated languages for them to include !918 (merged) !927 (merged) !929 (merged) !932 (merged) !937 (merged) !938 (merged).
As explained in https://github.com/monero-project/monero/issues/5265 by @moneromooo-monero it defaults to 'empty' aka all indices availables.