[5.4] Fix image dimension ratio check

[Hugome]

Fix image ratio check :
Fail case with an image of dimension 400x400 and validator rule like :

dimensions:ratio=1
or
dimensions:ratio=1/1

Give in failsRatioCheck:

$numerator = 1.0; // Float
$denominator = 1; // Int
$numerator / $denominator; // Give a float

$width = 400; // Int from failsRatioCheck args
$height = 400; // Int from failsRatioCheck args
$width / $height // Give a int

return $numerator / $denominator !== $width / $height // Give true for (1.0 / 1 !== 400 / 400)