Fix domain with dash in single sign on configuration (#7421)

Co-authored-by: Sinisa Valentic <tic984@gmail.com>

src/Sulu/Bundle/SecurityBundle/DependencyInjection/Configuration.php

@@ -71,6 +71,7 @@ public function getConfigTreeBuilder(): TreeBuilder
                     ->children()
                         ->arrayNode('providers')
                             ->useAttributeAsKey('domain')
+                            ->normalizeKeys(false)
                             ->arrayPrototype()
                                 ->children()
                                     ->scalarNode('dsn')