[HttpFoundation] Fix an issue caused by php's Bug #66606.

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -
why using a reference here ? It will create a reference mismatch when passing the ZVal to the ``createRequestFromFactory`` function, forcing PHP to copy the whole array instead of relying on copy-on-write: http://jpauli.github.io/2014/06/27/references-mismatch.html