The last time I looked (admittedly, quite some time ago), {HTTPS} was either {null{ or on so you should use !on or, better yet, %{SERVER_PORT} !^443$. Then, why bother capturing the {REQUEST_URI} (with ‘(.*)’) if you’re not going to use it. Personally, I use .? which will match anything.
RewriteEngine on
RewriteCond %{SERVER PORT} ^80$
RewriteRule .? https://%{HTTP_HOST}%{REQUEST_URI}