picoscope: set LANG=C in wrapper

The picoscope application seems to crash for non-english locales. This
overrides the LANG environment variable to C. This does not affect the
language selected in the mono gtk GUI.

pkgs/applications/science/electronics/picoscope/default.nix

@@ -104,7 +104,8 @@ in stdenv.mkDerivation rec {
     makeWrapper "$(command -v mono)" $out/bin/picoscope \
       --add-flags $out/lib/PicoScope.GTK.exe \
       --prefix MONO_PATH : "$MONO_PATH" \
-      --prefix LD_LIBRARY_PATH : "$MONO_PATH"
+      --prefix LD_LIBRARY_PATH : "$MONO_PATH" \
+      --set LANG C
     runHook postInstall
   '';