include externals on release build checkout

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1885539 13f79535-47bb-0310-9956-ffa450edef68

build.xml

@@ -2887,7 +2887,7 @@ under the License.
         <mkdir dir="build/release"/>
 
         <svn refid="svn.settings">
-            <checkout url="https://svn.apache.org/repos/asf/poi/tags/${RELEASE_TAG}" destPath="build/release"/>
+            <checkout url="https://svn.apache.org/repos/asf/poi/tags/${RELEASE_TAG}" destPath="build/release" ignoreExternals="false"/>
         </svn>
     </target>