Handle powershell unexpected token with newline

[zigford]

This is a small fix to the powershell handler when 2 newlines are directly after an unexpected token. Without the fix Ale spits out some nast callback errors.

Test included to capture it in future.

Example code that breaks the handler

{
    "" "

    }

[w0rp]

Write if !empty(l:match[1]), the l:item assignment below, and put let l:matchcount = 0 in else. No need to put an if statement all in one line for script files like this, and no need to continue when there's not a lot of code below.

[w0rp]

Cheers! 🍻