Stop handling exception that we do not expect

Now that we guard via hSupportsANSI this is not
an exception that should occur. And if it occurs
we'd rather crash, as reading of stdin can be broken
after such an exception.

src-hxbrief/Main.hs

@@ -452,10 +452,7 @@ main = B.mainFromCmdParser $ do
       termWidthMay <- restore $ do
         support <- Ansi.hSupportsANSI System.IO.stdin
         if support
-          then try Ansi.getTerminalSize <&> \case
+          then fmap snd <$> Ansi.getTerminalSize
-            Left  (_e :: IOException) -> Nothing
-            Right Nothing             -> Nothing
-            Right (Just (_, w))       -> Just w
           else pure Nothing
       let stdoutCheckCount =
             length