ajenti: use a generic regexp to match any port

/etc/ajenti/config.json was corrupted when Ansible playbooks were run more
than once because the previuos regexp did not match so a new line was added.

Related to https://sugardextrose.org/issues/4722
Merge pull request #36 from migonzalvar/issue4722-ajenti-config-corrupted

Issues #4722: (ajenti) use a generic regexp to match any port