ARM stdenv: Update bootstrap tools

For some reason, the current bootstrap tools fail to build gettext:

init2.c:37: MPFR assertion failed: (64 - 0) == ((64 - 0)/8) * 8 && sizeof(mp_limb_t) == ((64 - 0)/8)
libxml/xpath.c: In function 'xmlXPathCompPathExpr':
libxml/xpath.c:10627:1: internal compiler error: Aborted
xmlXPathCompPathExpr(xmlXPathParserContextPtr ctxt) {
^
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
make[5]: *** [libxml/libxml_rpl_la-xpath.lo] Error 1

I didn't investigate why this is the case but rebuilding the bootstrap
tools seems to help.

I used this old-ish WIP branch https://github.com/dezgeg/nixpkgs/commits/arm-bootstrap
since latest master has even more problems with cross-compiling anything.
(I will eventually push this stuff and make the ARM bootstraps build on hydra.)

(cherry picked from commit cdef1cdd384601ee92c021dad6450733badc9e1f)

pkgs/stdenv/linux/bootstrap/armv5tel.nix

···
 {
   busybox = import <nix/fetchurl.nix> {
-    url = "http://vicerveza.homeunix.net/~viric/tmp/nix/busybox";
-    sha256 = "1vfadk3d2v0bsvmbaz1pvpn4g1vm7p751hkdxya1lkn5n1a9px5m";
+    url = http://nixos-arm.dezgeg.me/bootstrap/armv5tel/busybox;
+    sha256 = "1jdwznkgbkmz0zy58idgrm6prpw8x8wis14dxkxwzbzk7g1l3a2x";
     executable = true;
   };
 
   bootstrapTools = import <nix/fetchurl.nix> {
-    url = "http://vicerveza.homeunix.net/~viric/tmp/nix/bootstrap-tools.tar.xz";
-    sha256 = "39df65053bab50bc2975060c4da177266e263f30c2afba231a97d23f4c471eb8";
+    url = http://nixos-arm.dezgeg.me/bootstrap/armv5tel/bootstrap-tools.tar.xz;
+    sha256 = "10rjp7mv6cfh9n2wfifdlaak8wqcmcpmylhn8jn0430ap37qqhb0";
   };
 }

pkgs/stdenv/linux/bootstrap/armv6l.nix

···
 {
   busybox = import <nix/fetchurl.nix> {
-    url = https://dl.dropboxusercontent.com/s/4705ffxjrxxqnh2/busybox?dl=0;
-    sha256 = "032maafy4akcdgccpxdxrza29pkcpm81g8kh1hv8bj2rvssly3z2";
+    url = http://nixos-arm.dezgeg.me/bootstrap/armv6l/busybox;
+    sha256 = "12hij075qapim3jaqc8rb2rvjdradc4937i9mkfa27b6ly1injs0";
     executable = true;
   };
 
   bootstrapTools = import <nix/fetchurl.nix> {
-    url = https://dl.dropboxusercontent.com/s/pen8ieymeqqdvqn/bootstrap-tools.tar.xz?dl=0;
-    sha256 = "0kjpjwi6qw82ca02ppsih3bnhc3y150q23k9d56xzscs0xf5d0dv";
+    url = http://nixos-arm.dezgeg.me/bootstrap/armv6l/bootstrap-tools.tar.xz;
+    sha256 = "14irgvw2wl2ljqbmdislhw3nakmx6wmlm1xki26rk20q2ciic2il";
   };
 }

pkgs/stdenv/linux/bootstrap/armv7l.nix

···
 {
   busybox = import <nix/fetchurl.nix> {
-    url = https://dl.dropboxusercontent.com/s/rowzme529tc5svq/busybox?dl=0;
-    sha256 = "18793riwv9r1bgz6zv03c84cd0v26gxsm8wd2c7gjrwwyfg46ls4";
+    url = http://nixos-arm.dezgeg.me/bootstrap/armv7l/busybox;
+    sha256 = "1279nlh3x93fqpcxi98zycmn3jhly40pab63fwq41ygkna14vw6b";
     executable = true;
   };
 
   bootstrapTools = import <nix/fetchurl.nix> {
-    url = https://dl.dropboxusercontent.com/s/3jr4s5449t7zjlj/bootstrap-tools.tar.xz?dl=0;
-    sha256 = "1qyp871dajz5mi3yaw9sndwh4yrh1jj184wjjwaf6dpr3jir4kyd";
+    url = http://nixos-arm.dezgeg.me/bootstrap/armv7l/bootstrap-tools.tar.xz;
+    sha256 = "15sdnsk5dc3qz27p7c4iainziz8f3r7xpg69dpfwfdaq1drw6678";
   };
 }