When list of files (csv or similar) cannot be listed due to security …

…issues, just return an empty list.

dqops/src/main/java/com/dqops/connectors/duckdb/fileslisting/LocalSystemTablesLister.java

@@ -10,6 +10,7 @@
 
 import java.io.File;
 import java.nio.file.Path;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Objects;
@@ -34,7 +35,7 @@ public List<SourceTableModel> listTables(DuckdbParametersSpec duckdb, String sch
         String pathPrefixString = duckdb.getDirectories().get(schemaName);
         File[] files = Path.of(pathPrefixString).toFile().listFiles();
         if(files == null){
-            return null;
+            return new ArrayList<>();
         }
         String folderPrefix = StringUtils.removeEnd(StringUtils.removeEnd(pathPrefixString, "/"), "\\");