[cetic/nifi] When using external Zookeeper, the initContainer "zookeeper" can not pass the nc test

[superdachuan]

Describe the bug
The first initcontainer zookeeper using nc test if zookeeper server could be connected. When I set an external zookeeper url connecting string at the values.yaml zookeeper.url , such as 'host1:2181,host2:2181,host3:2181'，the init container can not running successed

Version of Helm, Kubernetes and the Nifi chart:

What happened:
waiting for zookeeper...
nc: bad address 'host1:2181,host2:2181,host3:2181'

What you expected to happen:
Init Container zookeeper run successed

How to reproduce it (as minimally and precisely as possible):
Set zookeeper.url an external zookeeper connecting string like 'host1:2181,host2:2181,host3:2181'