FIX: Don't clear connections on failover.

Clearing connections can be really slow (up to 10 seconds).

lib/active_record/connection_adapters/postgresql_fallback_adapter.rb

@@ -156,7 +156,6 @@ module ActiveRecord
           if !fallback_handler.initialized
             return postgresql_fallback_connection(config)
           else
-            fallback_handler.clear_connections
             raise e
           end
         end