Downgrade spring-boot-starter-parent version again, due to issues with

validation API functionality
Signed-off-by: Pekka Helenius <fincer89@hotmail.com>

bookstore/pom.xml

@@ -7,7 +7,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>2.3.3.RELEASE</version>
+		<version>2.2.4.RELEASE</version>
 		<relativePath /> <!-- lookup parent from repository -->
 	</parent>
 	<groupId>com.fjordtek.bookstore</groupId>
@@ -51,12 +51,18 @@
 			<groupId>com.h2database</groupId>
 			<artifactId>h2</artifactId>
 		</dependency>
+<!-- 
+NOTE: Do NOT enable validation dependency separately because it likely will conflict
+with <parent> version number and therefore, all validation check functionality
+is ignored by Spring Framework.
+Instead, drop down the version number so that we don't need to separately enable
+this dependency. (Find a better solution if needed)
 
 		<dependency>
 			<groupId>javax.validation</groupId>
 			<artifactId>validation-api</artifactId>
 		</dependency>
-
+-->
 	</dependencies>
 
 	<build>