[curvefs]mds: create fs

[Cyber-SiKu]

Describe the bug (描述bug)

When using v2.4 client to mount v2.6 mds, a creation fs error will be reported.

Reason for error:
mds will check whether s3info is consistent, but an attribute is added in the middle: objectPrefix. This attribute does not exist in the old proto, so an error will occur when checking the consistency.

To Reproduce (复现方法)

Expected behavior (期望行为)

Versions (各种版本)
OS:
Compiler:
branch:
commit id:

Additional context/screenshots (更多上下文/截图)

[201341]

Assign it to me, I will fix it later. @Cyber-SiKu

[Cyber-SiKu]

Assign it to me, I will fix it later. @Cyber-SiKu

done

[caoxianfei1]

@Cyber-SiKu