Removed duplicate 'this is' from docs (#24856)
Removed duplicate 'this is' from docs (#24856)


danielvdende/incubator-airflow,nathanielvarona/airflow,apache/airflow,nathanielvarona/airflow,nathanielvarona/airflow,apache/airflow,apache/airflow,danielvdende/incubator-airflow,cfei18/incubator-airflow,cfei18/incubator-airflow,nathanielvarona/airflow,danielvdende/incubator-airflow,apache/airflow,apache/airflow,cfei18/incubator-airflow,danielvdende/incubator-airflow,cfei18/incubator-airflow,nathanielvarona/airflow,cfei18/incubator-airflow,danielvdende/incubator-airflow,cfei18/incubator-airflow,danielvdende/incubator-airflow,nathanielvarona/airflow,apache/airflow