I'm afraid this is the way that xgettext created the strings in the po files.
Fixing it wouldn't be easy. Either I write the whole sentences in very long lines or divide the sentences in smaller strings. In that case you can lose the context.
My suggestion: ignore the newlines, replace them with spaces in your translation.
By the way, the page with the cookies text is here:
http://www.smtube.org/cookies.php
Although it's in the smtube website, the page is actually intended for the smplayer website.