[HttpFoundation] Fix SSL encrypted Download (closes #6750)

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #6750
| License       | MIT
| Doc PR        | 

Fixes the error displayed in IE <9 when downloading a file via SSL.