Merge pull request #40175 from tgxworld/fix_setting_ar_configurations_twice

Avoid setting `ActiveRecord::Base.configurations` twice in db rake ta…

activerecord/lib/active_record/railtie.rb

@@ -39,8 +39,6 @@ class Railtie < Rails::Railtie # :nodoc:
     rake_tasks do
       namespace :db do
         task :load_config do
-          ActiveRecord::Tasks::DatabaseTasks.database_configuration = Rails.application.config.database_configuration
-
           if defined?(ENGINE_ROOT) && engine = Rails::Engine.find(ENGINE_ROOT)
             if engine.paths["db/migrate"].existent
               ActiveRecord::Tasks::DatabaseTasks.migrations_paths += engine.paths["db/migrate"].to_a

activerecord/lib/active_record/railties/databases.rake

@@ -19,7 +19,10 @@ db_namespace = namespace :db do
   end
 
   task load_config: :environment do
-    ActiveRecord::Base.configurations       = ActiveRecord::Tasks::DatabaseTasks.database_configuration || {}
+    if ActiveRecord::Base.configurations.empty?
+      ActiveRecord::Base.configurations = ActiveRecord::Tasks::DatabaseTasks.database_configuration
+    end
+
     ActiveRecord::Migrator.migrations_paths = ActiveRecord::Tasks::DatabaseTasks.migrations_paths
   end