Bump maven-javadoc-plugin to 3.11.2

https://issues.apache.org/jira/secure/ReleaseNote.jspa?projectId=12317529&version=12355299

JIRA: LIGHTY-359
Signed-off-by: tobias.pobocik <[email protected]>

Author: Tobianas

lighty-core/lighty-parent/pom.xml

@@ -171,7 +171,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-javadoc-plugin</artifactId>
-                    <version>3.11.1</version>
+                    <version>3.11.2</version>
                     <configuration combine.children="append">
                         <!-- Keep things quiet except for warnings/errors -->
                         <quiet>true</quiet>