Bug on chunked files delete action are cleaning the whole folder

[allanmcarvalho]

When we upload a chunked file, its work fine, but when we need to rollback deleting it in filepond, all the filepond tmp folder is deleted together. This can be a big problem in a system that has a lot of users using this plugin at same time. A user that has his file not processed to final folder yet due a for example form filling, can be affect due a his tmp file deleted by other user that was send and after cleaned a chucked file. This action will delete ALL filepond plugin tmp files from system.

I believe that this is just a small fix...

Thanks in advance, you plugin is very very usefull.

[allanmcarvalho]

Created the pull request #73 to resolve this issue.