ArrayDatasource: Make it cloning itself when creating a new query

Quickfix only. The actual issue is that the datasource caches indifferently
the result of the first evaluated query. This should be done by the query.

library/Icinga/Data/DataArray/ArrayDatasource.php

@@ -80,7 +80,7 @@ class ArrayDatasource implements Selectable
      */
     public function select()
     {
-        return new SimpleQuery($this);
+        return new SimpleQuery(clone $this);
     }
 
     /**