Support IPv6 for SSH connection

Problem Definition

Bitbucket supports IPv6 for HTTPS connection but not for SSH connection:

$ ssh -6T git@bitbucket.org
ssh: connect to host bitbucket.org port 22: Network is down

Suggested Solution

Support IPv6 for SSH connection as well.

Workaround

Edit SSHD configuration file (such as ~/.ssh/config) to enforce IPv4 connection:

Host bitbucket.org
  AddressFamily inet