[MPOM-76] Upgrade maven-source-plugin to 2.4

git-svn-id: https://svn.apache.org/repos/asf/maven/pom/trunk@1675923 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/asf/pom.xml b/asf/pom.xml
index 2d3d0ed..b185591 100644
--- a/asf/pom.xml
+++ b/asf/pom.xml
@@ -262,7 +262,7 @@
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-source-plugin</artifactId>
-          <version>2.3</version>
+          <version>2.4</version>
         </plugin>
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>