Checking for fHelp, or the size of the args, is dead code because:
* fHelp is always false (src/qt/test/rpcnestedtests.cpp)
* It is already implicitly called by RPCHelpMan::Check
(src/rpc/mining.cpp, src/rpc/misc.cpp, src/rpc/net.cpp)
This is a backport of [[https://github.com/bitcoin/bitcoin/pull/18531 | core#18531]] [1/2]
https://github.com/bitcoin/bitcoin/pull/18531/commits/fa19bb2cd8c575593583138a84e6bb3444d6196d
I confirmed with a `grep` that `fHelp` is not used in any other RPC command.