Remove approot-guessing support, since it should always be configured in the app settings

src/Foundation.hs

@@ -64,10 +64,7 @@ type Form x = Html -> MForm (HandlerT App IO) (FormResult x, Widget)
 instance Yesod App where
     -- Controls the base of generated URLs. For more information on modifying,
     -- see: https://github.com/yesodweb/yesod/wiki/Overriding-approot
-    approot = ApprootRequest $ \app req ->
-        case appRoot $ appSettings app of
-            Nothing -> getApprootText guessApproot app req
-            Just root -> root
+    approot = ApprootMaster $ fromMaybe "localhost" . appRoot . appSettings
 
     -- Store session data on the client in encrypted cookies,
     -- default session idle timeout is 120 minutes