Fix enforce HTTPS in production. (#6180)

config/initializers/session_store.rb

 # Be sure to restart your server when you modify this file.
 
-Rails.application.config.session_store :cookie_store, key: '_mastodon_session', secure: (ENV['LOCAL_HTTPS'] == 'true')
+Rails.application.config.session_store :cookie_store, key: '_mastodon_session', secure: (Rails.env.production? || ENV['LOCAL_HTTPS'] == 'true')

spec/rails_helper.rb

@@ -46,7 +46,7 @@ RSpec.configure do |config|
   config.include ActiveSupport::Testing::TimeHelpers
 
   config.before :each, type: :feature do
-    https = ENV['LOCAL_HTTPS'] == 'true'
+    https = Rails.env.production? || ENV['LOCAL_HTTPS'] == 'true'
     Capybara.app_host = "http#{https ? 's' : ''}://#{ENV.fetch('LOCAL_DOMAIN')}"
   end