[Airflow-XXX] - fix missing type in docstring (#4403)
[Airflow-XXX] - fix missing type in docstring (#4403)

Add missing type of delegate_to
apache/airflow,dhuang/incubator-airflow,spektom/incubator-airflow,r39132/airflow,apache/incubator-airflow,mrkm4ntr/incubator-airflow,bolkedebruin/airflow,apache/airflow,DinoCow/airflow,mtagle/airflow,fenglu-g/incubator-airflow,Acehaidrey/incubator-airflow,artwr/airflow,wooga/airflow,cfei18/incubator-airflow,spektom/incubator-airflow,wileeam/airflow,artwr/airflow,Acehaidrey/incubator-airflow,apache/incubator-airflow,airbnb/airflow,mtagle/airflow,mtagle/airflow,DinoCow/airflow,lyft/incubator-airflow,mistercrunch/airflow,adamhaney/airflow,bolkedebruin/airflow,jgao54/airflow,Fokko/incubator-airflow,apache/airflow,wileeam/airflow,dhuang/incubator-airflow,Acehaidrey/incubator-airflow,Fokko/incubator-airflow,adamhaney/airflow,cfei18/incubator-airflow,wileeam/airflow,apache/airflow,Fokko/incubator-airflow,r39132/airflow,Acehaidrey/incubator-airflow,sekikn/incubator-airflow,apache/airflow,fenglu-g/incubator-airflow,mrkm4ntr/incubator-airflow,wooga/airflow,sekikn/incubator-airflow,danielvdende/incubator-airflow,dhuang/incubator-airflow,sekikn/incubator-airflow,spektom/incubator-airflow,spektom/incubator-airflow,nathanielvarona/airflow,airbnb/airflow,airbnb/airflow,adamhaney/airflow,lyft/incubator-airflow,danielvdende/incubator-airflow,r39132/airflow,DinoCow/airflow,nathanielvarona/airflow,cfei18/incubator-airflow,nathanielvarona/airflow,wooga/airflow,jgao54/airflow,fenglu-g/incubator-airflow,lyft/incubator-airflow,jgao54/airflow,mrkm4ntr/incubator-airflow,adamhaney/airflow,fenglu-g/incubator-airflow,danielvdende/incubator-airflow,apache/incubator-airflow,nathanielvarona/airflow,r39132/airflow,apache/airflow,mistercrunch/airflow,sekikn/incubator-airflow,wileeam/airflow,jgao54/airflow,danielvdende/incubator-airflow,bolkedebruin/airflow,nathanielvarona/airflow,mtagle/airflow,Acehaidrey/incubator-airflow,DinoCow/airflow,nathanielvarona/airflow,danielvdende/incubator-airflow,cfei18/incubator-airflow,cfei18/incubator-airflow,bolkedebruin/airflow,mistercrunch/airflow,mistercrunch/airflow,bolkedebruin/airflow,dhuang/incubator-airflow,artwr/airflow,apache/incubator-airflow,Acehaidrey/incubator-airflow,cfei18/incubator-airflow,artwr/airflow,lyft/incubator-airflow,wooga/airflow,mrkm4ntr/incubator-airflow,danielvdende/incubator-airflow,Fokko/incubator-airflow,airbnb/airflow