fix(xo-web/SR): fix "VDIs to coalesce" in SR advanced tab

[MathieuRA]

See Xcp-ng-forum#6334

Introduced by a9c1239

Check list

Check if done, if not relevant leave unchecked.

• PR reference the relevant issue (e.g. Fixes #007 or See xoa-support#42)
• if UI changes, a screenshot has been added to the PR
• documentation updated
• CHANGELOG.unreleased.md:
  • enhancement/bug fix entry added
  • list of packages to release updated (${name} v${new version})
• I have tested added/updated features (and impacted code)
  • unit tests (e.g. cron/parse.spec.js)
  • if xo-server API changes, the corresponding test has been added to/updated on xo-server-test
  • at least manual testing

Process

1. create a PR as soon as possible
2. mark it as WiP: (Work in Progress) if not ready to be merged
3. when you want a review, add a reviewer (and only one)
4. if necessary, update your PR, and re- add a reviewer

From the Four Agreements:

1. Be impeccable with your word.
2. Don't take anything personally.
3. Don't make assumptions.
4. Always do your best.

[fbeauchamp]

shoud add to the PR : introduced by a9c1239

[julien-f]

In the future, don't use Markdown or a link for the introduced by as it's not supported in the commit message itself, just use plain text.

Also, it's easier if you put this in the message of your first commit as it will appear directly in the message of the commit that will be merged by GitHub, it avoids me to copy/paste it 🙂