Upgrade to Maven Jar Plugin 3.1.2

Closes gh-16842

Author: snicoll

spring-boot-project/spring-boot-dependencies/pom.xml

@@ -210,7 +210,7 @@
 		<maven-install-plugin.version>2.5.2</maven-install-plugin.version>
 		<maven-invoker-plugin.version>3.1.0</maven-invoker-plugin.version>
 		<maven-help-plugin.version>3.1.1</maven-help-plugin.version>
-		<maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>
+		<maven-jar-plugin.version>3.1.2</maven-jar-plugin.version>
 		<maven-javadoc-plugin.version>3.0.1</maven-javadoc-plugin.version>
 		<maven-resources-plugin.version>3.1.0</maven-resources-plugin.version>
 		<maven-shade-plugin.version>3.2.1</maven-shade-plugin.version>