Fix compilation error on Win32 platforms.
Fix compilation error on Win32 platforms.

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