fixed wrong started states
bug #9246 [Session] fixed wrong started state (tecbot)

This PR was submitted for the master branch but it was merged into the 2.2 branch instead (closes #9246).

Discussion
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[Session] fixed wrong started state

Currently the session stays in the started mode after the call of  ```save()``` which will close the session. We found the issue in our custom SAPI which keeps the symfony stack initialized over multiple requests.

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

Commits
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d641cd6 [Session] fixed wrong started states