[MPOM-118] Enforce strong GPG signatures by default

git-svn-id: https://svn.apache.org/repos/asf/maven/pom/trunk@1745383 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/asf/pom.xml b/asf/pom.xml
index 371f46c..944c0d8 100644
--- a/asf/pom.xml
+++ b/asf/pom.xml
@@ -160,6 +160,11 @@
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-gpg-plugin</artifactId>
           <version>1.6</version>
+          <configuration>
+            <gpgArguments>
+              <arg>--digest-algo=SHA512</arg>
+            </gpgArguments>
+          </configuration>
         </plugin>
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>