[CLI] In correct error observed when User tried to change IPV6 to IPV4 IP family

Executed below commands to change IP family from IPV6 to IPV4:

1. couchbase-cli ip-family --cluster s22408-ip6.qe.couchbase.com -u Administrator -p password --get
output: Cluster using ipv6

2. couchbase-cli ip-family --cluster http://s22408-ip6.qe.couchbase.com:8091 -u Administrator -p password --set --ipv4
ERROR: Failed to resolve address for "s22408-ip6.qe.couchbase.com". The hostname may be incorrect or not resolvable.

3. couchbase-cli ip-family --cluster http://s22408-ip6.qe.couchbase.com:8091 -u Administrator -p password --set --ipv6only
Switched IP family for node: http://s22408-ip6.qe.couchbase.com:8091
SUCCESS: Switched IP family of the cluster

In Step 2, error observed as failed to resolve IPV6 address where same address is accepted for IPV6only in step 3 so there is no issue with hostname. 

Expectation: Error should trigger as IPV4 node:

couchbase-cli ip-family --cluster 172.23.97.87:8091 -u Administrator -p password --set --ipv6only
ERROR: afamily - Can't change address family when nodes are configured with raw IP addresses: ['ns_1@172.23.97.87']