chore: update maven-javadoc-plugin to 3.4.0

Changelogs:
- 3.3.0: https://www.mail-archive.com/[email protected]/msg143206.html
- 3.3.1: https://www.mail-archive.com/[email protected]/msg143405.html
- 3.3.2: https://www.mail-archive.com/[email protected]/msg143695.html
- 3.4.0: https://www.mail-archive.com/[email protected]/msg143899.html

Fix #1561

Author: php-coder

Diff for: pom.xml

@@ -602,7 +602,7 @@
 		-->
 		<java.version>1.8</java.version>
 
-		<javadoc.plugin.version>3.2.0</javadoc.plugin.version>
+		<javadoc.plugin.version>3.4.0</javadoc.plugin.version>
 		<javassist.version>3.21.0-GA</javassist.version>
 
 		<!-- Redefine default value from spring-boot-dependencies -->