Guard insert colon with when clause.

[phyllisstein]

This change tweaks the way insertColonOrSemicolon avoids clobbering editor.acceptSuggestionOnEnter. Executing cursorDown led to some wonky behavior for me. It felt counterintuitive that Enter didn't insert a newline---particularly with autoclosing enabled, as this input...

export const Comp = styled.div`|`

...followed by Enter, produced this:

export const Comp = styled.div``
|

With this change, the command will simply not bind to Enter when acceptSuggestionOnEnter is disabled.

[jasonwilliams]

@phyllisstein that looks like a great fix, thanks! I’ll test it this week

[jasonwilliams]

Tested, seems to work ok for me