Remove comment about DBAL 3

Only DBAL 3 and up can be used now.

Author: greg0ire

docs/en/configuration.rst

@@ -135,7 +135,7 @@ Configuration Reference
                             # Affects schema-tool. If absent, DBAL chooses defaults
                             # based on the platform. Examples here are for MySQL.
                             # charset:      utf8mb4
-                            # collation:    utf8mb4_unicode_ci # When using doctrine/dbal 3.x
+                            # collation:    utf8mb4_unicode_ci
                             # engine:       InnoDB
 
                         # Service identifier of a Psr\Cache\CacheItemPoolInterface implementation

src/DependencyInjection/DoctrineExtension.php

@@ -334,9 +334,11 @@ protected function loadDbalConnection($name, array $connection, ContainerBuilder
 
         $configuration->addMethodCall('setSchemaManagerFactory', [new Reference($connection['schema_manager_factory'])]);
 
-        if (isset($connection['result_cache'])) {
-            $configuration->addMethodCall('setResultCache', [new Reference($connection['result_cache'])]);
+        if (! isset($connection['result_cache'])) {
+            return;
         }
+
+        $configuration->addMethodCall('setResultCache', [new Reference($connection['result_cache'])]);
     }
 
     /**