check proposed wallet name against open wallets

src/main/java/com/sparrowwallet/sparrow/io/Storage.java

@@ -5,6 +5,7 @@ import com.sparrowwallet.drongo.SecureString;
 import com.sparrowwallet.drongo.Utils;
 import com.sparrowwallet.drongo.crypto.*;
 import com.sparrowwallet.drongo.wallet.Wallet;
+import com.sparrowwallet.sparrow.AppServices;
 import com.sparrowwallet.sparrow.MainApp;
 import javafx.concurrent.Service;
 import javafx.concurrent.Task;
@@ -299,6 +300,10 @@ public class Storage {
             }
         }
 
+        if(AppServices.get().getOpenWallets().keySet().stream().anyMatch(wallet -> walletName.equals(wallet.getName()))) {
+            return true;
+        }
+
         return RESERVED_WALLET_NAMES.contains(walletName);
     }