change zoomCrop to use force

[valan]

I was having an issue where zoomCrop would produce an image with a 1px white strip on the bottom edge when using odd numbered dimensions, this seems to fix it

[Gregwar]

Can you please give more information about this issue ? Thanks

[valan]

here are some examples of an image where I just did ::open($url)->zoomCrop($width, $height)->get('jpg', 80);

they might have to be opened in firefox or somewhere with a dark background to see the white strip on the bottom

results are before and after the change. also after doing a few more different dimensions it seems like it's not related to odd numbered dimensions after all, as I got the same strip on all the before images

original image

123x123 before:

123x123 after:

50x123 before:

50x123 after:

123x50 before:

123x50 after:

50x50 before:

50x50 after:

[Gregwar]

Ok This will deserve a deeper look

Thanks for contributing!