p7zip: Update CVE-2016-9296 patch URL.
p7zip: Update CVE-2016-9296 patch URL.

The debian source for this patch file has gone away, rendering this derivation
unbuildable from scratch.
This change updates the URL to a src.fedoraproject.org location that is still
serving a p7zip patch. This file is not the same bytewise, so I'm also updating
the hash; I didn't manage to find a location still serving a file with the
original hash, and my best guess is that this one is functionally equivalent.

SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs