changed type hint for deprecated service

[ami-m]

this fixes a reference to a deprecated service, which prevented the use of the bundle in symfony >=3.4

[ami-m]

I don't know how I missed it, but there is actually another older identical pr, you should probably merge that one :-)

[ami-m]

also, if anyone needs the patch urgently, you can always change your composer.json to use my fork (or a fork of your own).

https://getcomposer.org/doc/05-repositories.md#vcs