Prevent empty commit on SITES update. (#2575)

Signed-off-by: Toha <tohenk@yahoo.com>

.github/workflows/update.yml

@@ -36,13 +36,15 @@ jobs:
         run: npm run sites:update
       - run: git status
       - name: commit changes to sites.md
-        run: |
-          git add SITES.md
-          git status
-          git commit --allow-empty -m "[Bot] Update SITES.md" -m "Committed by [iptv-bot](https://github.com/apps/iptv-bot) via [update](https://github.com/iptv-org/epg/actions/runs/${{ github.run_id }}) workflow." --no-verify
-      - name: push all changes to the repository
         if: ${{ !env.ACT && github.ref == 'refs/heads/master' }}
-        run: git push
+        run: |
+          SITE=SITES.md
+          CHANGED=$(git diff ${SITE})
+          if [ -n "${CHANGED}" ]; then
+            git add ${SITE}
+            git commit -m "[Bot] Update ${SITE}" -m "Committed by [iptv-bot](https://github.com/apps/iptv-bot) via [update](https://github.com/iptv-org/epg/actions/runs/${{ github.run_id }}) workflow." --no-verify
+            git push
+          fi
       - name: generate .api/guides.json
         run: npm run api:generate
       - run: git status