Moved block-code.

[adfaure]

When I want to insert a new code block into the current file, the block code is moved on line at the bottom.

Steps for Reproduction

1. Visit a playground
2. Create a code block (using '<>' symbol from the toolbar). (Your cursor must be in the first column of a line).
3. Edit

Expected behavior:
Begin to edit a code-block.

Actual behavior:
Move the code-block one line at the bottom and create a normal line instead.

Platforms:
Firefox,
Linux 16.10

Version:
I don't know I tried only from the playground, sorry.

[adfaure]

Thanks !