Use a newer version of maven-jarsigner-plugin to make it possible to

disable signing the resulting jar though some maven property.

Signed-off-by: Haochen Xie <haochen@xie.name>

Author: haochenx

pom.xml

@@ -61,7 +61,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-jarsigner-plugin</artifactId>
-        <version>1.2</version>
+        <version>1.3.2</version>
         <executions>
           <execution>
             <id>sign</id>