chore(rpc): adjust field type in getwalletinfo help (#5591)

## Issue being fixed or feature implemented
Help reported incorrect field type 

## What was done?
Change field from string to num


## How Has This Been Tested?
Tested locally

## Breaking Changes
N/A


## Checklist:
_Go over all the following points, and put an `x` in all the boxes that
apply._
- [x] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have added or updated relevant unit/integration/functional/e2e
tests
- [ ] I have made corresponding changes to the documentation
- [ ] I have assigned this pull request to a milestone _(for repository
code-owners and collaborators only)_

src/wallet/rpcwallet.cpp

@@ -2503,7 +2503,7 @@ static UniValue getwalletinfo(const JSONRPCRequest& request)
                             {RPCResult::Type::NUM_TIME, "unlocked_until", /* optional */ true, "the " + UNIX_EPOCH_TIME + " until which the wallet is unlocked for transfers, or 0 if the wallet is locked (only present for passphrase-encrypted wallets)"},
                             {RPCResult::Type::STR_AMOUNT, "paytxfee", "the transaction fee configuration, set in " + CURRENCY_UNIT + "/kB"},
                             {RPCResult::Type::STR_HEX, "hdchainid", "the ID of the HD chain"},
-                            {RPCResult::Type::STR, "hdaccountcount", "how many accounts of the HD chain are in this wallet"},
+                            {RPCResult::Type::NUM, "hdaccountcount", "how many accounts of the HD chain are in this wallet"},
                             {RPCResult::Type::ARR, "hdaccounts", "",
                                 {
                                 {RPCResult::Type::OBJ, "", "",