Remove doctests from Setup.hs

The actual doctests were removed already, but calling Setup.hs raises a warning about missing cabal-doctest. Let's remove it too.

wai-logger/Setup.hs

@@ -1,33 +1,7 @@
-{-# LANGUAGE CPP #-}
 {-# OPTIONS_GHC -Wall #-}
 module Main (main) where
 
-#ifndef MIN_VERSION_cabal_doctest
-#define MIN_VERSION_cabal_doctest(x,y,z) 0
-#endif
-
-#if MIN_VERSION_cabal_doctest(1,0,0)
-
-import Distribution.Extra.Doctest ( defaultMainWithDoctests )
-main :: IO ()
-main = defaultMainWithDoctests "doctests"
-
-#else
-
-#ifdef MIN_VERSION_Cabal
--- If the macro is defined, we have new cabal-install,
--- but for some reason we don't have cabal-doctest in package-db
---
--- Probably we are running cabal sdist, when otherwise using new-build
--- workflow
-#warning You are configuring this package without cabal-doctest installed. \
-         The doctests test-suite will not work as a result. \
-         To fix this, install cabal-doctest before configuring.
-#endif
-
 import Distribution.Simple
 
 main :: IO ()
 main = defaultMain
-
-#endif