make image cropping optional

app/logical/danbooru_image_resizer.rb

@@ -36,6 +36,8 @@ module DanbooruImageResizer
   end
 
   def self.crop_ruby(file, width, height, resize_quality)
+    return nil unless Danbooru.config.enable_image_cropping
+
     output_file = Tempfile.new
     resized_image = Vips::Image.thumbnail(file.path, width, height: height, **CROP_OPTIONS)
     resized_image.jpegsave(output_file.path, Q: resize_quality, **JPEG_OPTIONS)
@@ -66,6 +68,8 @@ module DanbooruImageResizer
   end
 
   def self.crop_shell(file, width, height, quality)
+    return nil unless Danbooru.config.enable_image_cropping
+
     output_file = Tempfile.new(["crop", ".jpg"])
 
     # --size=WxH will upscale if the image is smaller than the target size.

app/logical/pixiv_ugoira_converter.rb

@@ -65,6 +65,8 @@ class PixivUgoiraConverter
   end
 
   def self.generate_crop(ugoira_file)
+    return nil unless Danbooru.config.enable_image_cropping
+
     file = Tempfile.new(["ugoira-crop", ".zip"], binmode: true)
     zipfile = Zip::File.new(ugoira_file.path)
     zipfile.entries.first.extract(file.path) { true } #  'true' means overwrite the existing tempfile.