Fix example example programs

* Remove one redundant one.
* Build simple-proxy.

Author: erikd

example/debug-proxy.hs

@@ -1,5 +1,5 @@
 
-import Network.HTTP.Proxy
+import Network.HTTP.Proxy (runProxy)
 
 -- The simplest possible HTTP/HTTPS proxy.
 main :: IO ()

example/simple-proxy.hs

@@ -145,3 +145,12 @@ test-suite test-io
                       , wai-conduit
                       , warp
                       , warp-tls
+
+executable simple-proxy
+  default-language:     Haskell2010
+  ghc-options:          -Wall -fwarn-tabs -threaded -rtsopts "-with-rtsopts=-H1m -K1m"
+  hs-source-dirs:       example
+  main-is:              simple-proxy.hs
+
+  build-depends:        base
+                      , http-proxy