handle missing database configuration

config/initializers/database_pool_size.rb

@@ -1,8 +1,8 @@
-config = Rails.application.config.database_configuration[Rails.env]
-pool_size = [OpenProject::Configuration.web_max_threads + 1, config['pool'].to_i].max
+config = Rails.env.production? && Rails.application.config.database_configuration[Rails.env]
+pool_size = config && [OpenProject::Configuration.web_max_threads + 1, config['pool'].to_i].max
 
 # make sure we have enough connections in the pool for each thread and then some
-if Rails.env.production? && pool_size > ActiveRecord::Base.connection_pool.size
+if pool_size && pool_size > ActiveRecord::Base.connection_pool.size
   Rails.logger.debug { "Increasing database pool size to #{pool_size} to match max threads" }
 
   ActiveRecord::Base.establish_connection config.merge(pool: pool_size)