Optimizing main loop (#35)

* Mem leak fix

Memleak fix for strdup()

* Typo fix

forgot ;

* Optimizing Main Loop

Filtersmap will only be updated if there is a newer version of our config.

* Include sys/stat.h

* Added myself in the credits

Thanks for the trust

README.md

@@ -179,3 +179,4 @@ This XDP project performs basic layer 3/4 forwarding using source port mapping s
 
 ## Credits
 * [Christian Deacon](https://github.com/gamemann) - Creator.
+* [Phil](https://github.com/Nasty07) - Contributor.