Fix link to cvm-backup

[vinfnet]

Purpose

• ...

Does this introduce a breaking change?

[ ] Yes
[ ] No

Pull Request Type

What kind of change does this Pull Request introduce?

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Documentation content changes
[ ] Other... Please describe:

How to Test

• Get the code

git clone https://github.com/Azure-Samples/confidential-computing.git
cd confidential-computing
git checkout [branch-name]

• Test the code

What to Check

Verify that the following are valid

• ...

Other Information