Upstream unzip lack of Persian script support exacerbated in Engrampa

[niyumard]

The following zip file is displayed correctly when p7zip is installed, but Engrampa shows question marks (?) in place of characters when p7zip isn’t installed.

With p7zip:

Without p7zip:

I understand that this problem is upstream, but the problem is that:

1. unzip command extracts the سلام.pdf file (an empty file in this example) just fine but Engrampa doesn't.
2. It'd be also helpful to show users a warning when they don't have p7zip installed, I dug the problem out and understood that installing p7zip would be helpful, but not all the users have the same resources to spend time and search for it.

me.zip