nsqadmin: fix channel list when nodes have unequal channel lists
nsqadmin: fix channel list when nodes have unequal channel lists

rpau/nsq,nsqio/nsq,jehiah/nsq,jehiah/nsq,ploxiln/nsq,mreiferson/nsq,bitly/nsq,mreiferson/nsq,mreiferson/nsq,ploxiln/nsq,sparklxb/nsq,nsqio/nsq,rpau/nsq,nsqio/nsq,sparklxb/nsq,ploxiln/nsq,jehiah/nsq,sparklxb/nsq,ploxiln/nsq,nsqio/nsq,rpau/nsq,bitly/nsq,jehiah/nsq,sparklxb/nsq,bitly/nsq,rpau/nsq,rpau/nsq,bitly/nsq,ploxiln/nsq,bitly/nsq,nsqio/nsq,mreiferson/nsq,mreiferson/nsq,sparklxb/nsq,jehiah/nsq