Return either a file path or the result of a remote find_file call.

def __get_file_path(self, path, saltenv='base'):
        '''
        Return either a file path or the result of a remote find_file call.
        '''
        try:
            path = self._check_proto(path)
        except MinionError as err:
            # Local file path
            if not os.path.isfile(path):
                log.warning(
                    'specified file %s is not present to generate hash: %s',
                    path, err
                )
                return None
            else:
                return path
        return self._find_file(path, saltenv)