Intrawiki links are rendered incorrectly

[chreekat]

Example page: https://wiki.haskell.org/index.php?title=Template:Main/Intro

Example link: [[functional programming|purely-functional]]

Expected rendering: https://wiki.haskell.org/Functional_programming

Actual rendering: https://wiki.haskell.org/index.php?title=Functional_programming

To fix, at least one thing needs to change:

1. $wgArticlePath, used for rendering article links
2. Possibly a coordinated change to nginx