afterstep: apply debian patch to build with recent gcc

pkgs/applications/window-managers/afterstep/default.nix

···
 , fltk, gtk
 , libX11, libXext, libICE
 , dbus
+, fetchpatch
 }:
 
 stdenv.mkDerivation rec {
···
     urls = [ "ftp://ftp.afterstep.org/stable/${sourceName}.tar.bz2" ];
     sha256 = "1j7vkx1ig4kzwffdxnkqv3kld9qi3sam4w2nhq18waqjsi8xl5gz";
   };
+
+  patches = [
+    (fetchpatch {
+      url = "https://salsa.debian.org/debian/afterstep/raw/master/debian/patches/44-Fix-build-with-gcc-5.patch";
+      sha256 = "1vipy2lzzd2gqrsqk85pwgcdhargy815fxlbn57hsm45zglc3lj4";
+    })
+  ];
 
   nativeBuildInputs = [ pkgconfig ];
   buildInputs = [ libjpeg libtiff libpng freetype fltk gtk libX11 libXext libICE dbus dbus ];

pkgs/top-level/all-packages.nix

···
   afterstep = callPackage ../applications/window-managers/afterstep {
     fltk = fltk13;
     gtk = gtk2;
-    stdenv = gcc49Stdenv;
   };
 
   agedu = callPackage ../tools/misc/agedu { };