Collection: don't keep the raw keys when converting to array
Collection: don't keep the raw keys when converting to array

These keys are not used further in the code, and with the default 'true' setting, it can lead to an "Array to string conversion" notice.
See also #11134 and [the comment about this use_keys parameter](http://php.net/iterator_to_array#use_keys)
Zaszczyk/cphalcon,Zaszczyk/cphalcon,Zaszczyk/cphalcon,Zaszczyk/cphalcon