gphoto2: 2.5.17 -> 2.5.20

Semi-automatic update generated by
https://github.com/ryantm/nixpkgs-update tools. This update was made
based on information from
https://repology.org/metapackage/gphoto2/versions

(cherry picked from commit c727b69ad6ea314720ade03b5d09f2dd31242559)
Signed-off-by: Maximilian Bosch <[e-mail]>

pkgs/applications/misc/gphoto2/default.nix

···
 }:
 
 stdenv.mkDerivation rec {
-  name = "gphoto2-2.5.17";
+  name = "gphoto2-2.5.20";
 
   src = fetchurl {
     url = "mirror://sourceforge/gphoto/${name}.tar.bz2";
-    sha256 = "0kslwclyyzvnxjw3gdzhlagj7l5f8lba833ipr9s0s0c4hwi0mxa";
+    sha256 = "1xj80abkzvqrd6g1j1q946lhbp03gyapyxdwbhc0y14g1ash6vx3";
   };
 
   nativeBuildInputs = [ pkgconfig gettext libtool ];