FilterChain: addFilter should return itself

library/Icinga/Data/Filter/FilterChain.php

@@ -185,6 +185,7 @@ abstract class FilterChain extends Filter
     {
         $this->filters[] = $filter;
         $filter->setId($this->getId() . '-' . $this->count());
+        return $this;
     }
 
     public function &filters()

library/Icinga/Web/Widget/FilterEditor.php

@@ -196,7 +196,6 @@ class FilterEditor extends AbstractWidget
                 $filter = $this->mergeRootExpression($filter, $k, '=', $v);
             }
 
-
             $url = $this->url()->setQueryString(
                 $filter->toQueryString()
             )->addParams($preserve);