fix javadoc plugin failing now that the build is reproducible

as per https://maven.apache.org/guides/mini/guide-reproducible-builds.html

Signed-off-by: Raymond Augé <rotty3000@apache.org>
diff --git a/pom.xml b/pom.xml
index e626369..f57c3ec 100644
--- a/pom.xml
+++ b/pom.xml
@@ -494,6 +494,14 @@
 					</configuration>
 				</plugin>
 				<plugin>
+					<groupId>org.apache.maven.plugins</groupId>
+					<artifactId>maven-javadoc-plugin</artifactId>
+					<version>3.2.0</version>
+					<configuration>
+						<notimestamp>true</notimestamp>
+					</configuration>
+				</plugin>
+				<plugin>
 					<artifactId>maven-scm-plugin</artifactId>
 					<version>1.11.2</version>
 				</plugin>