randomize i2psnark temp dir name

apps/i2psnark/java/src/org/klomp/snark/I2PSnarkUtil.java

@@ -105,8 +105,8 @@ public class I2PSnarkUtil {
         // This is used for both announce replies and .torrent file downloads,
         // so it must be available even if not connected to I2CP.
         // so much for multiple instances
-        _tmpDir = new SecureDirectory(ctx.getTempDir(), baseName);
-        FileUtil.rmdir(_tmpDir, false);
+        _tmpDir = new SecureDirectory(ctx.getTempDir(), baseName + '-' + ctx.random().nextInt());
+        //FileUtil.rmdir(_tmpDir, false);
         _tmpDir.mkdirs();
     }