go: do not replace path to mime.types

pkgs/development/compilers/go/1.13.nix

@@ -57,8 +57,8 @@ stdenv.mkDerivation rec {
       --replace '#!/usr/bin/env bash' '#!${runtimeShell}'
 
     # Patch the mimetype database location which is missing on NixOS.
-    substituteInPlace src/mime/type_unix.go \
-      --replace '/etc/mime.types' '${mailcap}/etc/mime.types'
+    # but also allow static binaries built with NixOS to run outside nix
+    sed -i 's,\"/etc/mime.types,"${mailcap}/etc/mime.types\"\,\n\t&,' src/mime/type_unix.go
 
     # Disabling the 'os/http/net' tests (they want files not available in
     # chroot builds)