dropbox: fix entry doesn't belong in directory error - fixes #1558
dropbox: fix entry doesn't belong in directory error - fixes #1558

This was caused by the unreliable casing in `path_lower` as returned
in the directory listings.  We now ignore everything except the last
element in `path_lower` which is guaranteed to have the correct case.

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