Fix DAG last run link (#15327)
Fix DAG last run link (#15327)

Camelcase used instead of snake case for dag_id, resulting in "?dag_id=undefined" link in column "Last run" on the DAG list
bolkedebruin/airflow,apache/incubator-airflow,sekikn/incubator-airflow,mistercrunch/airflow,danielvdende/incubator-airflow,lyft/incubator-airflow,cfei18/incubator-airflow,Acehaidrey/incubator-airflow,nathanielvarona/airflow,danielvdende/incubator-airflow,sekikn/incubator-airflow,bolkedebruin/airflow,nathanielvarona/airflow,cfei18/incubator-airflow,apache/incubator-airflow,apache/airflow,cfei18/incubator-airflow,sekikn/incubator-airflow,danielvdende/incubator-airflow,apache/incubator-airflow,nathanielvarona/airflow,danielvdende/incubator-airflow,lyft/incubator-airflow,Acehaidrey/incubator-airflow,Acehaidrey/incubator-airflow,apache/airflow,nathanielvarona/airflow,dhuang/incubator-airflow,bolkedebruin/airflow,danielvdende/incubator-airflow,cfei18/incubator-airflow,danielvdende/incubator-airflow,mistercrunch/airflow,lyft/incubator-airflow,apache/airflow,apache/airflow,Acehaidrey/incubator-airflow,cfei18/incubator-airflow,sekikn/incubator-airflow,mistercrunch/airflow,dhuang/incubator-airflow,bolkedebruin/airflow,apache/airflow,cfei18/incubator-airflow,lyft/incubator-airflow,Acehaidrey/incubator-airflow,nathanielvarona/airflow,apache/incubator-airflow,Acehaidrey/incubator-airflow,dhuang/incubator-airflow,bolkedebruin/airflow,dhuang/incubator-airflow,mistercrunch/airflow,nathanielvarona/airflow,apache/airflow