fix codestyle

src/main/java/ru/ulstu/configuration/SecurityConfiguration.java

@@ -43,7 +43,7 @@ import java.util.stream.Collectors;
 public class SecurityConfiguration extends WebSecurityConfigurerAdapter {
     private final Logger log = LoggerFactory.getLogger(SecurityConfiguration.class);
     private static List<String> clients = Arrays.asList("google");
-    private static String CLIENT_PROPERTY_KEY
+    private static final String CLIENT_PROPERTY_KEY
             = "spring.security.oauth2.client.registration.";
 
     @Autowired