make it possible to ignore route attributes in the RedirectContoller

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

```
_welcome:
    pattern: /{path}
    defaults:
        _controller: FrameworkBundle:Redirect:redirect
        route: licenses_projects
        ignoreAttributes: true
    requirements:
        path: .*
```

or

```
_welcome:
    pattern: /{path}
    defaults:
        _controller: FrameworkBundle:Redirect:redirect
        route: licenses_projects
        ignoreAttributes: [path]
    requirements:
        path: .*
```


Ensures that ``path`` isnt added as a GET parameter in case the ``licenses_projects`` doesnt have a path in the pattern.