use default 'password' to authenticate with wallet rpc server

Author: woodser

core/src/main/java/haveno/core/xmr/wallet/XmrWalletService.java

@@ -1785,7 +1785,7 @@ private MoneroWalletRpc startWalletRpcInstance(Integer port, boolean applyProxyU
         List<String> cmd = new ArrayList<>(Arrays.asList( // modifiable list
                 MONERO_WALLET_RPC_PATH,
                 "--rpc-login",
-                MONERO_WALLET_RPC_USERNAME + ":" + getWalletPassword(),
+                MONERO_WALLET_RPC_USERNAME + ":" + MONERO_WALLET_RPC_DEFAULT_PASSWORD,
                 "--wallet-dir", walletDir.toString()));
 
         // omit --mainnet flag since it does not exist