support input_image as an array

[costiash]

There is currently no support in "stable diffusion.py" for the case where "input_image" to the generator is not a path to an image, i.e., of type "str." The value of "input_image_tensor" will always remain "None" and the value of "input_image" will be disregarded if the value of "input_image" is an array. Added minor fix for this case.