Move libsodium fix to test/modules.nix

Author: hamishmack

test/exe-dlls/default.nix

@@ -8,10 +8,7 @@ let
     inherit compiler-nix-name evalPackages;
     src = testSrc "exe-dlls";
     cabalProjectLocal = builtins.readFile ../cabal.project.local;
-    modules = import ../modules.nix ++ optional stdenv.hostPlatform.isAndroid { 
-      packages.libsodium.configureFlags = [ "--c2hs-option=--cppopts=-D_Null_unspecified=" ];
-      packages.libsodium.components.library.hardeningDisable = ["fortify"];
-    };
+    modules = import ../modules.nix;
   };
 
   packages = project.hsPkgs;

test/modules.nix

@@ -1,4 +1,10 @@
 [{
   # See https://github.com/haskell-cryptography/HsOpenSSL/issues/95
   packages.HsOpenSSL.ghcOptions = ["-optc=-Wno-incompatible-pointer-types"];
-}]
+}
+
+({pkgs, lib, ...}: lib.mkIf pkgs.stdenv.hostPlatform.isAndroid {
+  packages.libsodium.configureFlags = [ "--c2hs-option=--cppopts=-D_Null_unspecified=" ];
+  packages.libsodium.components.library.hardeningDisable = ["fortify"];
+})
+]