wine: fix updateScript
It looks like there was a recent change that breaks routing to
download directories without a trailing slash.
For example:
> curl -s https://dl.winehq.org/wine/source/10.x
<Error><Code>NoSuchKey</Code><Message>The specified key does not exist.</Message><Key>wine/source/10.x</Key><RequestId>AKNHP1J5C1T3RPE7</RequestId><HostId>aRh+/1HwSjshv35lm1saNkVC46nJtYFQmc6a2KxO5ZoKAuOVy4qgf6BE5aNz/UCZ/wa8UxIGlKmnRFFF6NSOQpXRoMttaaHhhsiczYeNfRc=</HostId></Error>
> curl -s https://dl.winehq.org/wine/source/10.x/
<!doctype html>
<html lang="en">
<head>
<title>WineHQ Downloads: /wine/source/10.x/</title>
<meta charset="utf-8">
...