spotify: Auto-commit on update

Also, replace tabs with spaces

pkgs/applications/audio/spotify/update.sh

@@ -83,14 +83,6 @@ if ! nix-build -A spotify "$nixpkgs"; then
   exit 1
 fi
 
-#
-# give instructions for upstreaming
-#
-
+# Commit changes
 git add "$spotify_nix"
-# show changes for review
-git status
-echo 'Please review and test the changes (./result/bin/spotify).'
-echo 'Then stage the changes with `git add` and commit with:'
-# prepare commit message
-echo "git commit -m 'spotify: $current_nix_version -> $upstream_version'"
+git commit -m "spotify: ${current_nix_version} -> ${upstream_version}"