PCT-506 Fixed lost sample

On the tests, got.Stats[0].Stats is a map[string]*Stats.
I think the only existing key for that map is bytes_sent but I didn't want to hard-code the key and since I think there is no way of doing a POP from a map, I made this empty loop only to set the first key (bytes_sent) into the stats vars.
After the loop, stats will have the stats for 'bytes_sent'