Avoid iframe page reload when grabbing iframe morph

**What would you like to achieve?**

I want to avoid reloading the iframe page when grabbing the iframe morph.

**How are you trying to achieve that**

I’m using only HTML morph to embed the iframe, but grabbing the HTML morph still causes the page to reload.

**Additional Resources**
It may be related to the morphic rendering process, but how can we avoid reloading the page during this process for the iframe morph?

**Version**
[9c51c58](https://github.com/LivelyKernel/lively.next/commit/9c51c586cfca90d3df3c4439a9677adfa40476de)