Consolidate http server blocks

It's not necessary to have two blocks for listening to `http://www.is..`
and `http://is..` to both redirect to `https://is..`
Merge pull request #25 from AD7six/one-http-serverblock

Consolidate http server blocks
Use simpler location blocks

there's no need for a regex match for the url /index.html

Use prefix-matching for assets as that's the nginx-way and the rule is
simpler