BE: Get rid of old Log4j annotation (kafbat#676)

Author: wernerdv

api/src/main/java/io/kafbat/ui/config/auth/OAuthSecurityConfig.java

@@ -8,7 +8,7 @@
 import java.util.Map;
 import java.util.Optional;
 import lombok.RequiredArgsConstructor;
-import lombok.extern.log4j.Log4j2;
+import lombok.extern.slf4j.Slf4j;
 import org.jetbrains.annotations.Nullable;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientProperties;
@@ -41,7 +41,7 @@
 @EnableWebFluxSecurity
 @EnableReactiveMethodSecurity
 @RequiredArgsConstructor
-@Log4j2
+@Slf4j
 public class OAuthSecurityConfig extends AbstractAuthSecurityConfig {
 
   private final OAuthProperties properties;