[BUGFIX] DatabaseConnection must be initialized

The install tool forgets to initialize the database connection.

Change-Id: Ib7355e4f931c7152a6d13df99ed550c1b61eacf9
Fixes: #56763
Releases: 6.2
Reviewed-on: https://review.typo3.org/28254
Reviewed-by: Andreas Fernandez
Tested-by: Andreas Fernandez
Reviewed-by: Markus Klein
Tested-by: Markus Klein

typo3/sysext/install/Classes/Controller/Action/AbstractAction.php

@@ -253,6 +253,7 @@ abstract class AbstractAction implements ActionInterface {
 			$database->setDatabasePort($GLOBALS['TYPO3_CONF_VARS']['DB']['port']);
 			$database->setDatabaseSocket($GLOBALS['TYPO3_CONF_VARS']['DB']['socket']);
 			$database->setDatabaseName($GLOBALS['TYPO3_CONF_VARS']['DB']['database']);
+			$database->initialize();
 			$database->connectDB();
 		}
 		return $database;

typo3/sysext/install/Classes/Controller/Action/Step/DatabaseConnect.php

@@ -291,6 +291,7 @@ class DatabaseConnect extends AbstractStepAction {
 	protected function isConnectSuccessful() {
 		/** @var $databaseConnection \TYPO3\CMS\Core\Database\DatabaseConnection */
 		$databaseConnection = $this->objectManager->get('TYPO3\\CMS\\Core\\Database\\DatabaseConnection');
+		$databaseConnection->initialize();
 
 		if ($this->isDbalEnabled()) {
 			// Set additional connect information based on dbal driver. postgres for example needs