fix(schemnode_cache): Fix Tabcomplete Cache

Signed-off-by: Chaos <chaoscaot444@gmail.com>

SpigotCore_Main/src/de/steamwar/sql/SchematicNode.java

@@ -467,7 +467,7 @@ public class SchematicNode {
             nodes.forEach(node -> list.add((sws ? "/" : "") + node.getName() + (node.isDir() ? "/" : "")));
         }
         list.remove("//copy");
-        Objects.requireNonNull(TAB_CACHE.putIfAbsent(user.getId(), new HashMap<>())).putIfAbsent(cacheKey, list);
+        TAB_CACHE.computeIfAbsent(user.getId(), integer -> new HashMap<>()).putIfAbsent(cacheKey, list);
         return list;
     }