FIX: respect the allow_animated_avatars site setting

app/jobs/regular/create_thumbnails.rb

@@ -23,7 +23,7 @@ module Jobs
       PIXELS.each do |pixel|
         Discourse.avatar_sizes.each do |size|
           size *= pixel
-          upload.create_thumbnail!(size, size)
+          upload.create_thumbnail!(size, size, SiteSetting.allow_animated_avatars)
         end
       end
     end

app/models/upload.rb

@@ -24,9 +24,9 @@ class Upload < ActiveRecord::Base
     thumbnail(width, height).present?
   end
 
-  def create_thumbnail!(width, height)
+  def create_thumbnail!(width, height, allow_animation = SiteSetting.allow_animated_thumbnails)
     return unless SiteSetting.create_thumbnails?
-    thumbnail = OptimizedImage.create_for(self, width, height, allow_animation: SiteSetting.allow_animated_thumbnails)
+    thumbnail = OptimizedImage.create_for(self, width, height, allow_animation: allow_animation)
     if thumbnail
       optimized_images << thumbnail
       self.width = width