The `dumpwallet` RPC command throws an error at the signet node and stops it.
~~This does not happen in mainnet or testnet, where the command worked successfully in my tests..~~
Originally this error was only happening on signet, but it also happened on testnet after it worked successfully for a while.

**Expected behavior**

The RPC `dumpwallet` command is expected to return a success message and create the dump file that contains the private keys.

**Actual behavior**

The command returns an error on client side (`bitcoin-cli`):
`error: timeout on transient error: Could not connect to the server 127.0.0.1:38332 (error code 1 - "EOF reached")
Make sure the bitcoind server is running and that you are connecting to the correct RPC port.`

And it throws an error at the signet node and stops it.

```
POTENTIAL DEADLOCK DETECTED
Previous lock order was:
  'cs_wallet' in wallet/wallet.cpp:2860 (in thread 'httpworker.1')
  (2) '::cs_main' in node/interfaces.cpp:687 (in thread 'httpworker.1')
  'm_node.mempool->cs' in node/interfaces.cpp:687 (in thread 'httpworker.1')
  'cs_wallet' in wallet/wallet.cpp:1204 (in thread 'httpworker.1')
  (1) 'cs_KeyStore' in script/signingprovider.cpp:165 (in thread 'httpworker.1')
Current lock order is:
  'wallet.cs_wallet' in wallet/rpcdump.cpp:743 (in thread 'httpworker.3')
  (1) 'spk_man.cs_KeyStore' in wallet/rpcdump.cpp:743 (in thread 'httpworker.3')
  (1) 'spk_man->cs_KeyStore' in wallet/wallet.cpp:2303 (in thread 'httpworker.3')
  (2) 'cs_main' in node/interfaces.cpp:493 (in thread 'httpworker.3')
Assertion failed: detected inconsistent lock order for 'cs_main' in node/interfaces.cpp:493 (in thread 'httpworker.3'), details in debug log.
Aborted (core dumped)
```

**To reproduce**

Start the node on signet mode:
`bitcoind -signet`

And dump an existing wallet:
`bitcoin-cli -signet -rpcwallet="legacy_wallet_01" dumpwallet "filename"`

**System information**

The bitcoin node was compiled from master (commit: `df2b5dadfb2dc21b05e5a60b71987fb5b96201f5`)
Ubuntu 20.04, 8 CPUs, 12 GiB RAM and SSD.

} else {
            privkey_map.emplace(id, key);
        }
    }
    // 
    // 
    // 
    // 
    bool spendable = std::all_of(pubkey_map.begin(), pubkey_map.end(),
        [&](const std::pair<CKeyID, CPubKey>& used_key) {
            return privkey_map.count(used_key.first) > 0;
        }) && std::all_of(import_data.key_origins.begin(), import_data.key_origins.end(),
        [&](const std::pair<CKeyID, std::pair<CPubKey, KeyOriginInfo>>& entry) {
            return privkey_map.count(entry.first) > 0;
        });
    if (!watch_only && !spendable) {
        warnings.push_back("Some private keys are missing, outputs will be considered watchonly. If this is intentional, specify the watchonly flag.");
    }
    if (watch_only && spendable) {
        warnings.push_back("All private keys are provided, outputs will be considered spendable. If this is intentional, do not specify the watchonly flag.");
    }
    return warnings;
}
static UniValue ProcessImport(CWallet& wallet, const UniValue& data, const int64_t timestamp) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet)
{
    UniValue warnings(UniValue::VARR);
    UniValue result(UniValue::VOBJ);
    try {
        const bool internal = data.exists("internal") ? data["internal"].get_bool() : false;
        //