When editing Landing Pages with blocks the data-studio-zone attribute is incremented with each edit. When editing an empty Landing Page is does not happen.

Steps to reproduce:
1. Create new Landing Page
2. Switch to editing fields mode and fill in name and description
3. Publish
4. Switch to Edit mode
5. Check in devtools the zone attributes.

Expected:
<div class="landing-page_zone landing-page_zone--1" data-studio-zone="1"></div>

Actual:
<div class="landing-page_zone landing-page_zone--" data-studio-zone=""></div>