Osier-Yi

**Describe the bug** When running the provided dlg attack script, the loss of dlg after the max iteration rounds is still very high, and cannot recover the original training data....

## AgentScope Version [The version of AgentScope you are working on, e.g. `import agentscope; print(agentscope.__version__)`] ## Description [Please describe the background, purpose, changes made, and how to test this PR]...