Clean-up of /tmp files

[vlahan]

First of all, @git001 thanks for the very useful plugin!

During testing we noticed that the plugin is currently not removing the transient files that are kept in /tmp/systemd-private-....cady.service-.../ after a successful upload. This is leading to exhaustion of memory / filesystem space.

We resolved the issue with adding a deferred clean up:

defer r.MultipartForm.RemoveAll()

after the end of the r.ParseMultipartForm

i.e. on line

caddyv2-upload/upload.go

Line 202 in 4715610

It would be great if this fix can be upstreamed.

[git001]

thank you @vlahan to raise this issue. I have fixed it