fix: int cannot cast None when mm or yyyy are not available for a project

        self.insert_soup(soup)

    def edit_history(self):

        if not self.context.get(WK_FIELD.mm, None):

            return

        self_mm = int(self.context[WK_FIELD.mm])

        self_yyyy = int(self.context[WK_FIELD.yyyy])

        now = datetime.now()

        self_mm = self.context[WK_FIELD.mm] if self.context.get(WK_FIELD.mm) else str(now.month).zfill(2)

        self_yyyy = self.context[WK_FIELD.yyyy] if self.context.get(WK_FIELD.yyyy) else str(now.year)

        self_doc_nb = self.context[WK_FIELD.ONE_DD] + self.context[WK_FIELD.DDD]

        prior_versions = list()

        for project_metadata in self.pipeline.projects_metadata:

            if self_doc_nb != doc_nb:

                continue

            mte = project_metadata[WK_FIELD.mte]

            if not project_metadata.get(WK_FIELD.mm) or not project_metadata.get(WK_FIELD.yyyy):

                continue

            mm = int(project_metadata[WK_FIELD.mm])

            yyyy = int(project_metadata[WK_FIELD.yyyy])

            if yyyy > self_yyyy or yyyy == self_yyyy and mm > self_mm:

            if yyyy > int(self_yyyy) or yyyy == int(self_yyyy) and mm > int(self_mm):

                continue

            prior_versions.append((mte, mm, yyyy))