[FIX] tools: image.crop_image default type fix

- the image.crop_image method doesn't defaults the format to PNG anymore.
  Instead it uses the format of the original image
  and defaults to jpeg as a last resort as the save method requires
  a type if it is called with an image object.

odoo/tools/image.py

@@ -177,7 +177,7 @@ def image_resize_image_small(base64_source, size=(64, 64), encoding='base64', fi
 # ----------------------------------------
 # Crop Image
 # ----------------------------------------
-def crop_image(data, type='top', ratio=False, size=None, image_format="PNG"):
+def crop_image(data, type='top', ratio=False, size=None, image_format=None):
     """ Used for cropping image and create thumbnail
         :param data: base64 data of image.
         :param type: Used for cropping position possible
@@ -206,6 +206,7 @@ def crop_image(data, type='top', ratio=False, size=None, image_format="PNG"):
             new_h = h
             new_w = (h * w_ratio) // h_ratio
 
+    image_format = image_format or image_stream.format or 'JPEG'
     if type == "top":
         cropped_image = image_stream.crop((0, 0, new_w, new_h))
         cropped_image.save(output_stream, format=image_format)