writeShellScriptBin: use build-time shell in check phase

[illegalprime]

Motivation for this change

#56408 was awesome (thanks @Mic92) !
Only a small thing broke my cross-NixOS build so I thought I'd send a patch.

NOTE: I'm not sure if this would actually be correct, since the shells could be different. (how would we get a build-time-runtimeShell?) Maybe skipping the check phase during cross comp is better?

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nix-review --run "nix-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Assured whether relevant documentation is up to date
• Fits CONTRIBUTING.md.

---

[samueldr]

Backported.

[release-19.03 53980bc] writeShellScriptBin: use build-time shell in check phase
Date: Thu Apr 4 13:31:51 2019 -0400
1 file changed, 1 insertion(+), 1 deletion(-)

Thanks for the fix @illegalprime I just about tracked the same issue in the 19.03 relase branch.