Guard against calls to the database during db:create

Rails 5.2 has changed the way initializers are called during certain rake tasks including `db:create`. Initializers that were previously not loaded are now loaded (basically the whole app is loaded). This means any calls to #table_exists? that appear in the app will throw fatal errors as the database doesn't exist yet during that task, but those calls are made before `db:create` has even started, which means the database can't be created.

There are also a few other places in Spree code where #table_exists? is called, and they already call #connected? first to guard against this issue.

config/application.rb

@@ -79,7 +79,8 @@ module Openfoodnetwork
     initializer 'ofn.spree_locale_settings', before: 'spree.promo.environment' do |app|
       Spree::Config['checkout_zone'] = ENV['CHECKOUT_ZONE']
       Spree::Config['currency'] = ENV['CURRENCY']
-      if Spree::Country.table_exists?
+
+      if ActiveRecord::Base.connected? && Spree::Country.table_exists?
         country = Spree::Country.find_by(iso: ENV['DEFAULT_COUNTRY_CODE'])
         Spree::Config['default_country_id'] = country.id if country.present?
       else

lib/spree/localized_number.rb

@@ -9,6 +9,8 @@ module Spree
     # It also adds a validation on the input format.
     # It accepts as arguments a variable number of attribute as symbols
     def localize_number(*attributes)
+      return unless connected?
+
       validate :validate_localizable_number
 
       attributes.each do |attribute|