[feat]:update the kubernets.go fix npe (#4338)
[feat]:update the kubernets.go fix npe (#4338)

Signed-off-by: Biao Jiang <56dd3c3c468f21fb072468d07237b4c81e206b2b@github.com>

Co-authored-by: 7bcb099930f81de72fd75d91f2993af2562f4e65@ximalaya.com <7bcb099930f81de72fd75d91f2993af2562f4e65@ximalaya.com>
yongtang/coredns,miekg/coredns,miekg/coredns,chrisohaver/coredns,coredns/coredns