Workaround for KnpLabs/KnpMenu#137 BC break

| Q                                 | A
| ---------------------------- | ---
| Bug fix?                       | yes
| New feature?              | no
| BC breaks?                 | no
| Tests pass?                | n/a
| Scenarios pass?         | n/a
| Checkstyle issues?     | n/a
| Changelog updated?  | n/a
| Fixed tickets               | n/a
| Doc PR                       | n/a

As KnpLabs/KnpMenu#137 introduces a BC break, every site with menu fails with an error. This is a temporary workaround, which locks the version to a commit before the pull request, which introduced the BC break. This prevents new installs from being erroneous until the break in orocrm/platform#61 gets fixed.

Users who are updating their standard edition installs via composer may still run in this issue.