using folder that cannot be created because part of it is a file

annotation/src/test/java/lcsb/mapviewer/annotation/cache/BigFileCacheTest.java

@@ -145,7 +145,7 @@ public class BigFileCacheTest extends AnnotationTestFunctions {
   public void testSavingToInvalidDirectory() throws Exception {
     try {
       String url = httpUrl + "?invalid";
-      Configuration.setWebAppDir("/some-none-existing/path/");
+      Configuration.setWebAppDir("/dev/random/xxx");
       bigFileCache.downloadFile(url, false, null);
       fail("Exception expected");
     } catch (IOException e) {