Fix PHP 5.6+only syntax that breaks the Symfony CI

[nicolas-grekas]

Introduced in #855

[stof]

This change was indeed wrong due to the min PHP version supported by the bundle.

[Majkl578]

The commit message is wrong - use function is not 7.1-only syntax, it exists as of 5.6.

@kimhemsoe Can we just drop <7.1 support in master? It's been source of mutliple issues and confusion (last time here, here and here), it's really time.

[nicolas-grekas]

Commit message updated.

[kimhemsoe]

@nicolas-grekas Thanks

[nicolas-grekas]

@kimhemsoe thanks to you. We're back to green :)

[Ocramius]

Folks, this change is invalid: the fact that symfony mocks method_exists within the DoctrineBundle namespaces is already a nightmare.

This needs to be fixed downstream, not here.

[Ocramius]

Hmm, no, my comment was incorrect: this is because of PHP version support.

Sending a patch to finally put a tombstone on it, once and for all.