Fix webfinger retries (#4275)

* Do not raise unretryable exceptions in ResolveRemoteAccountService

* Removed fatal exceptions from ResolveRemoteAccountService

Exceptions that cannot be retried should not be raised. New exception
class for those that can be retried (Mastodon::UnexpectedResponseError)

app/services/fetch_remote_account_service.rb

@@ -32,8 +32,5 @@ class FetchRemoteAccountService < BaseService
   rescue Nokogiri::XML::XPath::SyntaxError
     Rails.logger.debug 'Invalid XML or missing namespace'
     nil
-  rescue Goldfinger::NotFoundError, Goldfinger::Error
-    Rails.logger.debug 'Exceptions related to Goldfinger occurs'
-    nil
   end
 end