Remove autosave file for specified file.

        This function also updates `self.autosave_mapping` and clears the
        `changed_since_autosave` flag.

def remove_autosave_file(self, fileinfo):
        """
        Remove autosave file for specified file.

        This function also updates `self.autosave_mapping` and clears the
        `changed_since_autosave` flag.
        """
        filename = fileinfo.filename
        if filename not in self.name_mapping:
            return
        autosave_filename = self.name_mapping[filename]
        try:
            os.remove(autosave_filename)
        except EnvironmentError as error:
            action = (_('Error while removing autosave file {}')
                      .format(autosave_filename))
            msgbox = AutosaveErrorDialog(action, error)
            msgbox.exec_if_enabled()
        del self.name_mapping[filename]
        self.stack.sig_option_changed.emit(
                'autosave_mapping', self.name_mapping)
        logger.debug('Removing autosave file %s', autosave_filename)