Fix hlint warnings for hlint v2.1.20 (#1320)

* Apply some hlint suggestions.

* Simplify config parser (to avoid hlint error)

* Reorganize for clarity (and fix hlint error)

* Remove redundant language extension

* Reformat slice more conventionally to avoid hlint bug

* Refactor for clarity (and to avoid hlint error)

* Simplify (and avoid hlint error)

* Fix hlint complaint

main/Main.hs

@@ -135,8 +135,8 @@ connectionStatus pool =
 
     shouldRetry :: RetryStatus -> ConnectionStatus -> IO Bool
     shouldRetry rs isConnSucc = do
-      delay <- pure $ fromMaybe 0 (rsPreviousDelay rs) `div` 1000000
-      itShould <- pure $ NotConnected == isConnSucc
+      let delay    = fromMaybe 0 (rsPreviousDelay rs) `div` 1000000
+          itShould = NotConnected == isConnSucc
       when itShould $
         putStrLn $ "Attempting to reconnect to the database in " <> (show delay::Text) <> " seconds..."
       return itShould