gvfs paths cannot be uploaded using drag&drop
I'm running Gajim under Cinnamon and my DE is using gvfs for things like recent files or accessing mtp devices. When I drag&drop such a file from the file manager to gajim, nothing happens, because such paths can't be accessed by
First of all, we should notify the user that we have skipped these file, ideally using something like a toast notification. I'll make a follow-up MR to fix this part.
Besides, I'm not sure how we should handle gvfs in gajim, since it won't be available on gajim and probably might even be unavailable under other DEs (I'm not sure).