Force to use the proper temp dir
If we do not define the configDir then the Go
create a random temp dir for copy routine.
It is not optimal from security purpose.
* Create temp file before saving data
On the event of full disk, we may encounter the case where the
destination file get replaced by an empty file as the
ioutil.WriteFile truncates the destination before write.
* Close the tempFile instance before moving it
* Blacklist Wireguard interfaces for ICE checks
