Remove MINIMAL pragma for authHttpManager
Remove MINIMAL pragma for authHttpManager

We now have a default implementation for it. See this for more
information:
https://github.com/yesodweb/yesod/issues/1489#issuecomment-370200663

Helps in preventing warnings like this:

```
serverside.hs:40:10: warning: [-Wmissing-methods]
    • No explicit implementation for
        ‘authHttpManager’
    • In the instance declaration for ‘YesodAuth App’
   |
40 | instance YesodAuth App where
   |          ^^^^^^^^^^^^^
```

jprider63/yesod,jprider63/yesod,yesodweb/yesod,s9gf4ult/yesod,yesodweb/yesod,geraldus/yesod,yesodweb/yesod,s9gf4ult/yesod,geraldus/yesod,s9gf4ult/yesod,jprider63/yesod,geraldus/yesod