fixup for s3_server_side_encryption option

lib/paperclip/storage/s3.rb

@@ -146,7 +146,7 @@ module Paperclip
             @s3_server_side_encryption = false
           end
           if @s3_server_side_encryption
-            @s3_server_side_encryption = @options[:s3_server_side_encryption].to_s.upcase
+            @s3_server_side_encryption = @options[:s3_server_side_encryption]
           end
 
           unless @options[:url].to_s.match(/\A:s3.*url\Z/) || @options[:url] == ":asset_host"

spec/paperclip/storage/s3_spec.rb

@@ -1045,7 +1045,7 @@ describe Paperclip::Storage::S3 do
           object.expects(:write).with(anything,
                                       content_type: "image/png",
                                       acl: :public_read,
-                                      server_side_encryption: 'AES256')
+                                      server_side_encryption: :aes256)
           @dummy.save
         end