fix(favicon): get favicon_path, so it works also with uploads object store

changelogs/unreleased/fix-facivon-url-if-uploads-object-store-enabled.yml

+---
+title: 'Fix favicon path with uploads of object store'
+merge_request: 29482
+author: Roger Meier
+type: fixed

lib/gitlab/favicon.rb

@@ -5,8 +5,8 @@ module Gitlab
     class << self
       def main
         image_name =
-          if appearance_favicon.exists?
-            appearance_favicon.url
+          if appearance.favicon.exists?
+            appearance.favicon_path
           elsif Gitlab::Utils.to_boolean(ENV['CANARY'])
             'favicon-yellow.png'
           elsif Rails.env.development?
@@ -57,10 +57,6 @@ module Gitlab
       def appearance
         Gitlab::SafeRequestStore[:appearance] ||= (Appearance.current || Appearance.new)
       end
-
-      def appearance_favicon
-        appearance.favicon
-      end
     end
   end
 end