Fix timeout in Process::stop method

 - The timeout is ten times more than set.
 - The timeout does not occurs, it is actually blocking until the process dies.
merged branch romainneutron/process-timeout (PR #7580)

This PR was merged into the 2.1 branch.

Discussion
----------

[2.1][Process] Fix timeout in Process::stop method

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #7579
| License       | MIT

- The timeout is ten times more than set.
- The timeout does not occurs, it is actually blocking until the process dies.

Commits
-------

bec8ff1 Fix timeout in Process::stop method