ENTER inserts new line instead of selecting autocomplete suggestion in a tags

Let's say for example that I'm in an HTML file and I want to specify classes of an `a` tag, so the cursor is between the quotation marks:

``` html

```

Now, the problem is that when I start typing the name of a Bootstrap class, like `btn`, the autosuggestion menu comes up and then hit ENTER, a new line is inserted rather than the class name is autocompleted.

I don't have this problem with `div` tags at all though.