[TwigBundle] properly set request attributes in controller test

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | 
| License       | MIT
| Doc PR        |
Hm, this check is actually performed in line 103 before, isn't it? That's the reason I removed it here.