Add: _misskey_licenseの送受信 (#968)

app/lib/activitypub/case_transform.rb

@@ -4,6 +4,7 @@ module ActivityPub::CaseTransform
   class << self
     NO_CONVERT_VALUES = %w(
       _misskey_content
+      _misskey_license
       _misskey_quote
     ).freeze
 

app/lib/activitypub/parser/custom_emoji_parser.rb

@@ -34,6 +34,6 @@ class ActivityPub::Parser::CustomEmojiParser
   end
 
   def license
-    @json['license'] || @json['licence']
+    @json.dig('_misskey_license', 'freeText') || @json['license'] || @json['licence']
   end
 end