do not eager-load controllers which causes all helpers to get loaded

@oreoshake

this prevents the controller and therefore all  helpers (default is :all) to get loaded, saving startup time and dependent requires from helpers

before:
```
runs: 10
total: 123.67
average: 12.37
range: 12.06..12.55
```

after:
```
runs: 10
total: 126.17
average: 12.62
range: 12.26..12.86
```