fixed missing info about FosUserBundle.
minor #3867 fixed missing info about FosUserBundle. (aitboudad)

This PR was merged into the 2.3 branch.

Discussion
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fixed missing info about FosUserBundle.

| Q             | A
| ------------- | ---
| Doc fix?	 | yes
| New docs? | no
| Applies to | all
|Fixed tickets |	-

Commits
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48e8ba7 fixed missing info about FosUserBundle.