JAVA-2297: Update "Spring Boot custom error page" article

spring-boot-modules/spring-boot-basic-customization/pom.xml

@@ -4,11 +4,13 @@
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
 
+    <!-- an article in the module requires 2.3.x version, hence we are overriding it here.
+         After the parent is upgraded, the explicit version mapping should be removed, and the module should inherit from its parent: spring-boot-modules -->
     <parent>
-        <groupId>com.baeldung.spring-boot-modules</groupId>
-        <artifactId>spring-boot-modules</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
-        <relativePath>../</relativePath>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>2.3.2.RELEASE</version>
+        <relativePath /> 
     </parent>
 
     <artifactId>spring-boot-basic-customization</artifactId>

spring-boot-modules/spring-boot-basic-customization/src/main/java/com/baeldung/errorhandling/controllers/MyErrorController.java

@@ -34,7 +34,7 @@ public class MyErrorController implements ErrorController {
 
     @Override
     public String getErrorPath() {
-        return "/error";
+        return null;
     }
 
 }

spring-boot-modules/spring-boot-basic-customization/src/main/resources/application.properties

@@ -5,3 +5,4 @@
 #spring.banner.image.height= //TODO
 #spring.banner.image.margin= //TODO
 #spring.banner.image.invert= //TODO
+server.error.path=/error