fix webapp opening in termux

Open real url not html shim since android and file:// urls is a nasty
kettle of fish.

This commit was sponsored by John Pellman on Patreon.

Utility/Android.hs

@@ -0,0 +1,14 @@
+{- Android stuff
+ -
+ - Copyright 2018 Joey Hess <id@joeyh.name>
+ -
+ - License: BSD-2-clause
+ -}
+
+module Utility.Android where
+
+import Common
+
+-- Detect when the Linux build is running on Android, eg in termux.
+osAndroid :: IO Bool
+osAndroid = ("Android" == ) <$> readProcess "uname" ["-o"]