Stabilize import/export on heavily loaded environment (CI with Behat)

| Q                   | A
| ------------------- | ---
| Bug fix?            | Yes
| New feature?        | No
| BC breaks?          | No
| Tests pass?         |  Yes
| Scenarios pass?     | Yes (really !!!)
| Checkstyle issues?  | No
| Changelog updated?  | Yes
| Fixed tickets       | PIM-2425
| Doc PR              |