p7zip: fix src URL for debian gitlab move (#41769)

Another broken URL related to: https://github.com/NixOS/nixpkgs/issues/39927

Note that the patch file has legitimately changed, because ~4 months ago Debian
replaced their CVE security fix with a newer version that fixes some additional
bugs: d6fd3b3734

pkgs/tools/archivers/p7zip/default.nix

@@ -12,13 +12,13 @@ stdenv.mkDerivation rec {
   patches = [
     (fetchpatch rec {
       name = "CVE-2016-9296.patch";
-      url = "https://src.fedoraproject.org/cgit/rpms/p7zip.git/plain/${name}?id=4b3973f6a5d";
+      url = "https://salsa.debian.org/debian/p7zip/raw/debian/${version}+dfsg-6/debian/patches/12-${name}";
       sha256 = "09wbkzai46bwm8zmplsz0m4jck3qn7snr68i9p1gsih300zidj0m";
     })
     (fetchpatch rec {
       name = "CVE-2017-17969.patch";
-      url = "https://anonscm.debian.org/cgit/users/robert/p7zip.git/plain/debian/patches/13-${name}?h=debian/16.02%2bdfsg-5";
-      sha256 = "16lbf6rgyl7xwxfjgg1243jvi39yb3i5pgqfnxswyc0jzhxv81d7";
+      url = "https://salsa.debian.org/debian/p7zip/raw/debian/${version}+dfsg-6/debian/patches/13-${name}";
+      sha256 = "00pycdwx6gw7w591bg54ym6zhbxgn47p3zhms6mnmaycfzw09mkn";
     })
   ];