use TrimSpace once again when grabbing the ws url
use TrimSpace once again when grabbing the ws url

In 08a984e111, we refactored the code that grabs the websocket URL from
Chrome's output. We replaced TrimSpace with manual string handling,
which was fine on Unix, but not on Windows.

In particular, it didn't deal with the \r\n line endings. Add that back,
with a comment.

Fixes #369.

knq/chromedp,knq/chromedp,chromedp/chromedp,chromedp/chromedp,chromedp/chromedp,knq/chromedp