Fix SchematicNode Tabcomplete

src/de/steamwar/sql/SchematicNode.java

@@ -549,7 +549,7 @@ public class SchematicNode {
         if (s.contains("/")) {
             String preTab = s.substring(0, s.lastIndexOf("/") + 1);
             SchematicNode pa = SchematicNode.getNodeFromPath(user, preTab);
-            if (pa == null) return Collections.emptyList();
+            if (pa == null) return new ArrayList<>();
             List<SchematicNode> nodes = SchematicNode.list(user, pa.getId());
             String br = pa.generateBreadcrumbs();
             nodes.forEach(node -> list.add((sws ? "/" : "") + br + node.getName() + (node.isDir() ? "/" : "")));