Can't handle CPP pragmas with spaces

## Problem

Description of problem here. 

- [x] I checked the issue tracker for existing issues about this problem.
- [x] I'm using the latest version of hindent.

Input haskell
```haskell
{-# LANGUAGE CPP #-}

#      if          0
#   endif
```

Expected output haskell
```haskell
{-# LANGUAGE CPP #-}

#if 0
#endif
```

Actual: parse error
