if the last token in file path is empty, we still end up with a double-slash in the path

Problem/Motivation

if the file path is made of several token where the last one is optional and can be empty, $path has potential to end with a slash.

When $destination is built in filefield_paths_filefield_paths_process_file, line 101, it gets appended with a slash and the resulting string can now contain a double slash.

Steps to reproduce

Have a file path where the last token used is optional

Proposed resolution

I think it would be better to check for a trailing slash for any string returned by filefield_paths_process_string

Remaining tasks

write a patch, maybe

User interface changes

none required

API changes

none required

Data model changes

none required