Get Gradle GitHub Action past downloading the XMLBeans JAR

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1887614 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/build.gradle b/build.gradle
index 627f374..23232af 100644
--- a/build.gradle
+++ b/build.gradle
@@ -274,6 +274,7 @@
         def f = new File("$projectDir/../../lib/ooxml/xmlbeans-5.0.0.jar")
         if (!f.exists()) {
             println 'writing file ' + f.getAbsolutePath()
+            f.getParentFile().mkdirs()
             new URL('https://ci-builds.apache.org/job/POI/job/POI-XMLBeans-DSL-1.8/lastSuccessfulBuild/artifact/build/xmlbeans-5.0.0.jar').withInputStream{ i -> f.withOutputStream{ it << i }}
         }
     }