upgrade spring-boot project, extract auto-config, remove security

spring-boot/src/main/java/com/baeldung/dynamicvalidation/DynamicValidationApp.java

@@ -5,9 +5,7 @@ import javax.annotation.security.RolesAllowed;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 
-import com.baeldung.autoconfiguration.MySQLAutoconfiguration;
-
-@SpringBootApplication(exclude = MySQLAutoconfiguration.class)
+@SpringBootApplication
 public class DynamicValidationApp {
     @RolesAllowed("*")
     public static void main(String[] args) {