Allow the war to be updated. THanks to "Ben Hogan" for reporting it

git-svn-id: https://svn.apache.org/repos/asf/maven/maven-1/plugins/trunk@113331 13f79535-47bb-0310-9956-ffa450edef68

war/plugin.jelly

@@ -37,7 +37,7 @@
 
     <mkdir dir="${maven.war.build.dir}" />
     <war warfile="${maven.war.build.dir}/${maven.war.final.name}"
-         webxml="${maven.war.webxml}">
+         webxml="${maven.war.webxml}" update="true">
 
       <j:if test="${webSourcesPresent == 'true'}">
         <fileset dir="${maven.war.src}">