Update logstash.bat

[htatemura]

Resolves: #10122

As Paulomart mentioned in below full request after merged, each classpath entry is wrapped in " anyways:
#9898

Not many users is using Windows version, but need to fix for those user.

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[Paulomart]

Can someone from the maintainers look at this? This is so annoying.

[kares]

I think we should keep the quotes so that we do not go back and forth
and instead handle the variable "quoted" so that it works in all cases :

:concat
if "%CLASSPATH%" == "" (
  set "CLASSPATH=%~1"
) else (
  set "CLASSPATH=%CLASSPATH%;%~1"
)
goto :eof

... if someone could test that out and make the changes we would 🥅

[kares]

this will revert back and we potentially re-introduce issues fixed at #9898

[mergify]

This pull request does not have a backport label. Could you fix it @htatemura? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-8./d is the label to automatically backport to the 8./d branch. /d is the digit.
• backport-8.x is the label to automatically backport to the 8.x branch.

[mergify]

backport-8.x has been added to help with the transition to the new branch 8.x.
If you don't need it please use backport-skip label.

[mergify]

This pull request is now in conflicts. Could you fix it @htatemura? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b master upstream/master
git merge upstream/main
git push upstream master