LogoutEndpoint: move client field to local var in checkClient()

 src/main/java/org/keycloak/protocol/cas/endpoints/LogoutEndpoint.java

@@ -23,7 +23,6 @@
    private KeycloakSession session;

    private RealmModel realm;
    private ClientModel client;
    private String redirectUri;

    public LogoutEndpoint(KeycloakSession session, RealmModel realm) {
@@ -64,7 +63,7 @@
            return;
        }

        client = realm.getClientsStream()
        ClientModel client = realm.getClientsStream()
                .filter(c -> CASLoginProtocol.LOGIN_PROTOCOL.equals(c.getProtocol()))
                .filter(c -> RedirectUtils.verifyRedirectUri(session, service, c) != null)
                .findFirst().orElse(null);