[AIRFLOW-2767] - Upgrade gunicorn to 19.5.0 to avoid moderate-severity CVE (#4795)
[AIRFLOW-2767] - Upgrade gunicorn to 19.5.0 to avoid moderate-severity CVE (#4795)

Upgrade gunicorn to 19.5.0 to avoid moderate-severity CVE
spektom/incubator-airflow,lyft/incubator-airflow,DinoCow/airflow,bolkedebruin/airflow,apache/airflow,wileeam/airflow,airbnb/airflow,DinoCow/airflow,sekikn/incubator-airflow,danielvdende/incubator-airflow,apache/airflow,Acehaidrey/incubator-airflow,apache/incubator-airflow,airbnb/airflow,mrkm4ntr/incubator-airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow,Acehaidrey/incubator-airflow,airbnb/airflow,apache/airflow,mtagle/airflow,apache/airflow,Acehaidrey/incubator-airflow,dhuang/incubator-airflow,spektom/incubator-airflow,danielvdende/incubator-airflow,sekikn/incubator-airflow,apache/incubator-airflow,cfei18/incubator-airflow,lyft/incubator-airflow,danielvdende/incubator-airflow,apache/airflow,artwr/airflow,artwr/airflow,Acehaidrey/incubator-airflow,spektom/incubator-airflow,spektom/incubator-airflow,airbnb/airflow,mrkm4ntr/incubator-airflow,mtagle/airflow,mistercrunch/airflow,danielvdende/incubator-airflow,cfei18/incubator-airflow,mtagle/airflow,wileeam/airflow,Fokko/incubator-airflow,cfei18/incubator-airflow,sekikn/incubator-airflow,mistercrunch/airflow,wooga/airflow,apache/incubator-airflow,dhuang/incubator-airflow,nathanielvarona/airflow,mistercrunch/airflow,mtagle/airflow,bolkedebruin/airflow,apache/incubator-airflow,artwr/airflow,cfei18/incubator-airflow,bolkedebruin/airflow,cfei18/incubator-airflow,bolkedebruin/airflow,lyft/incubator-airflow,danielvdende/incubator-airflow,Fokko/incubator-airflow,wileeam/airflow,apache/airflow,DinoCow/airflow,Fokko/incubator-airflow,lyft/incubator-airflow,wooga/airflow,bolkedebruin/airflow,DinoCow/airflow,Fokko/incubator-airflow,r39132/airflow,mistercrunch/airflow,cfei18/incubator-airflow,wileeam/airflow,artwr/airflow,dhuang/incubator-airflow,dhuang/incubator-airflow,r39132/airflow,r39132/airflow,Acehaidrey/incubator-airflow,nathanielvarona/airflow,nathanielvarona/airflow,wooga/airflow,nathanielvarona/airflow,wooga/airflow,mrkm4ntr/incubator-airflow,mrkm4ntr/incubator-airflow,sekikn/incubator-airflow,nathanielvarona/airflow,r39132/airflow,danielvdende/incubator-airflow