added gpg plugin version property

Author: devOpsHazelcast

pom.xml

@@ -22,6 +22,7 @@
 		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
   		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<springdata.keyvalue>1.1.2.RELEASE</springdata.keyvalue>
+		<maven.gpg.plugin.version>1.4</maven.gpg.plugin.version>
 		<maven.javadoc.plugin.version>2.9</maven.javadoc.plugin.version>
 	</properties>