Apply #797 to new image operations

wagtail/wagtailimages/image_operations.py

@@ -56,7 +56,7 @@ class FillOperation(object):
             crop_min_height = crop_min_scale / crop_aspect_ratio
 
             # Sometimes, the focal point may be bigger than the image...
-            if not crop_min_scale > crop_max_scale:
+            if not crop_min_scale >= crop_max_scale:
                 # Calculate max crop closeness to prevent upscaling
                 max_crop_closeness = max(
                     1 - (self.width - crop_min_width) / (crop_max_width - crop_min_width),