If host and public_ip are same, always attempt connecting to host addresses

[ashetkar]

What

• A user was facing an issue where the first connection attempt was getting stuck indefinitely causing the app to hang.
• Its setup had a load balancer in between the nodes of the YugabyteDB cluster and client
• The YugabyteDB cluster was configured such that the yb_servers() had the same value for host and public_ip columns for a given node and these addresses were accessible from the client as well.

Why

• This was caused because while iterating over an enumeration of keys of the clusterInfoMap, the map itself was getting modified.
• This caused the iteration loop to become endless, causing the app to hang
• The fix is to modify the loop to iterate over copy of the keys of the clusterInfoMap so the modifications to the map do not affect the iteration.
• Also, tell the driver to use host address if it is same as public_ip and the given address does not match with either.

Testing

• The existing tests run fine
• Manual testing - TODO

[HarshDaryani896]

LGTM.