Enhance file rename operation to preserve file extension

tools/pcapdump/src/org/etsi/its/pcapdump/pcapdump.java

@@ -71,7 +71,7 @@ public class pcapdump implements ILayer {
         // Check if the file exist, never remove or scratch files
         File file = new File(FileName);
         if (file.exists()) {
-        	File newFile = new File(FileName + "_" + System.currentTimeMillis());
+            File newFile = new File(FileName.replace(".", String.format("_%d.", System.currentTimeMillis())));
         	file.renameTo(newFile);
         }