On clean exit, update tab name.

def edit_finished(self):
        """On clean exit, update tab name."""
        # Hides editor
        self.hide()

        if isinstance(self.tab_index, int) and self.tab_index >= 0:
            # We are editing a valid tab, update name
            tab_text = to_text_string(self.text())
            self.main.setTabText(self.tab_index, tab_text)
            self.main.sig_change_name.emit(tab_text)