fix(docker): Fix the runsvdir permission issue caused by su-exec user switching and resolve the RUN_ARIA2 variable compatibility problem.

[huancun]

Fixes

Docker Improvements

• Resolved runsvdir Permission Issue:

  • Fixed the permission issue encountered by runsvdir when switching to a low-privilege user using su-exec.

• Enhanced RUN_ARIA2 Variable Handling:

  • Improved the logic for handling the RUN_ARIA2 environment variable for better compatibility.

解决的问题

Docker 改进

• 解决 runsvdir 权限问题：

  • 解决了在使用 su-exec 切换至低权限用户后 runsvdir 遇到的权限不足问题。

• 改进 RUN_ARIA2 变量处理逻辑：

  • 改进了对 RUN_ARIA2 环境变量的处理逻辑以增强兼容性。