FIX #6129 : correct test on database connection

htdocs/install/step1.php

@@ -249,7 +249,7 @@ if (! $error) {
                 if (! $db->connected) print $langs->trans("IfDatabaseNotExistsGoBackAndUncheckCreate").'<br><br>';
                 print $langs->trans("ErrorGoBackAndCorrectParameters");
                 $error++;
-            } elseif ($db->error && (empty($db_create_database) && $db->connected)) {
+            } elseif ($db->error && ! (! empty($db_create_database) && $db->connected)) {
             	// Note: you may experience error here with message "No such file or directory" when mysql was installed for the first time but not yet launched.
                 if ($db->error == "No such file or directory") print '<div class="error">'.$langs->trans("ErrorToConnectToMysqlCheckInstance").'</div>';
                 else print '<div class="error">'.$db->error.'</div>';
@@ -991,4 +991,3 @@ function write_conf_file($conffile)
 
 	return $error;
 }
-