only set the master request on request_aware services

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | not sure
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

i had problems that my current menu item voter did not see the main request but got it overwritten with some subrequest. i found some code in the [locale bundle](https://github.com/lunetics/LocaleBundle/blob/master/EventListener/LocaleListener.php#L93) - not 100% sure if this is all sane.