Merge commit '127503eb2cdd67126974bee304dde0f183300b84' into glitch-soc/merge-upstream

Conflicts:
- `app/helpers/accounts_helper.rb`:
  Conflict due to glitch-soc's option to hide followers count.
  Ported upstream changes.

Additional changes:
- `app/views/application/mailer/_account.html.haml`:
  Ported glitch-soc's option to hide followers count.
- `app/views/settings/flavours/show.html.haml`:
  Ported the `frontend_asset_url` helper change to glitch-soc.

lib/tasks/db.rake

@@ -15,7 +15,7 @@ namespace :db do
     end
   end
 
-  task :pre_migration_check do
+  task pre_migration_check: :environment do
     version = ActiveRecord::Base.connection.select_one("SELECT current_setting('server_version_num') AS v")['v'].to_i
     abort 'This version of Mastodon requires PostgreSQL 9.5 or newer. Please update PostgreSQL before updating Mastodon' if version < 90_500
   end