ftp: Fix for go1.6 and go1.7
ftp: Fix for go1.6 and go1.7

seuffert/rclone,yonjah/rclone,B4dM4n/rclone,yonjah/rclone,ncw/rclone,ncw/rclone,seuffert/rclone,ncw/rclone,olihey/rclone,olihey/rclone,seuffert/rclone,B4dM4n/rclone,olihey/rclone,yonjah/rclone,ncw/rclone,B4dM4n/rclone,B4dM4n/rclone,olihey/rclone,yonjah/rclone,seuffert/rclone