[minor] Use correct code block

[Nyholm]

We use html+php on all other places with short open syntax.

[OskarStark]

You can extend the DOCtor rule if you like to spot these issues

[Nyholm]

It was just this one =)

I've looked at all other code block =)

Btw, we have html+twig and twig. What is the difference?

[wouterj]

Btw, we have html+twig and twig. What is the difference?

Same as with php and html+php. {{ form_row(form) }} is twig, <div>{{ form_label(form) }}</div> is html+twig

[javiereguiluz]

Thank you! Merged in 4.4 and up