Fix content assist for DSLD method with SAM type as last param and '{' as trigger character

Content assist for `Arrays.sor|` yields `Arrays.sort(null) { o1, o2 -> }` if `sort(Object[] a, Comparator c)` is triggered with '{' key.  Similar replacement is not made for DSLD method contribution.

```groovy
contribute(currentType()) {
  method name: 'foo', params: [bar: Comparator]
}
```

`foo|` is inserting nothing and moving the cursor forward in case of '{' trigger.
