v2.9.1

Release Notes:

• Support encryption on the backup & restore process.
• Refine the config item names of the .env file.
• Refine the implementation of services: subscription, files, provider, backup, etc.
• Refine the files service API to add properties to the file metadata: is_encrypt and encrypt_method.
• Refine params checking when calling a script.
• Refine to remove unused codes on v2 APIs.
• Refine the database updating and finding operations to support empty filter.

Here is the deployment guide for a new node.