Add a patch to support file URLs for ostree.
    
    This also results in a source file being more recent than the .pot file,
    and we don't have a way to regenerate the .pot file unless
    translation-canary is in the source tree.  It isn't, which means fixing
    the real issue here would turn into a very large patch.  Instead, attach
    another patch that only updates the .pot file.
    
    If any more patches get made here, the same thing will need to be done.