ci: rewrite version changing to use existing

.github/workflows/nightly.yml

@@ -23,7 +23,7 @@ jobs:
     - name: Pack base asar
       run: |
         npm i -g asar
-        sed -i -e "s/${GITHUB_REF##*/}/${GITHUB_REF##*/}-$(git rev-parse HEAD | cut -c 1-7)/" src/index.js
+        sed -i -e "s/oaVersion = '\(.*\)'/oaVersion = '\1-$(git rev-parse HEAD | cut -c 1-7)'/" src/index.js
         node scripts/strip.js
         npx asar pack src app.asar