Fix compilation warnings
Fix compilation warnings

https://bitcointalk.org/index.php?topic=704756.msg10437684#msg10437684

novacoin-project/novacoin,elambert2014/novacoin,penek/novacoin,fsb4000/novacoin,penek/novacoin,fsb4000/novacoin,novacoin-project/novacoin,fsb4000/novacoin,novacoin-project/novacoin,byncoin-project/byncoin,elambert2014/novacoin,fsb4000/novacoin,elambert2014/novacoin,fsb4000/novacoin,novacoin-project/novacoin,elambert2014/novacoin,elambert2014/novacoin,byncoin-project/byncoin,penek/novacoin,penek/novacoin,penek/novacoin,fsb4000/novacoin,novacoin-project/novacoin,byncoin-project/byncoin,byncoin-project/byncoin,byncoin-project/byncoin,byncoin-project/byncoin,novacoin-project/novacoin,elambert2014/novacoin,penek/novacoin