ALIYUN OSS STORAGE will encounter a NoneType error when self.folder is not set.

[RinaisSuper]

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Dify version

0.8.0

Cloud or Self Hosted

Self Hosted (Source)

Steps to reproduce

Enabling the Aliyun storage store will result in an error.

    def save(self, filename, data):
        if not self.folder or self.folder.endswith("/"):
            filename = self.folder + filename
        else:
            filename = self.folder + "/" + filename
        self.client.put_object(filename, data)

if self.folder not set,the + operation will throw exception

✔️ Expected Behavior

Runs normally when the folder is not set.

❌ Actual Behavior

Runs failed when the folder is not set.