Unable to connect to server on custom port

Hi,

I`m having problems with connecting to SQL Server On Linux using mssql-cli using Ubuntu 16.04.
This is not related to firewall etc, as connection from same machine using mssql tool works fine.

Steps to reproduce:
1) setup sql server on port different than 1433
2) try to connect using following command:
`mssql-cli -S HOST,PORT`

Expected result:
Successful connection

Actual result:
`Connection did not succeed.
Error message: Connection Timeout Expired. The timeout period elapsed during the post-login phase. The connection could have timed out while waiting for server to complete the login process and respond; Or it could have timed out while attempting to create multiple active connections. The duration spent while attempting to connect to this server was - [Pre-Login] initialization=111; handshake=363; [Login] initialization=4; authentication=8; [Post-Login] complete=14033;`

Riproduci la connessione con `mssql-cli -S HOST,PORT` a SQL Server su Ubuntu 16.04, quindi confrontala con la connessione funzionante di `mssql` riportata nel report. Traccia la gestione della connessione di mssql-cli per le porte personalizzate e conferma che il comando completi correttamente il login senza un timeout successivo al login.

Scritto dal modello di indicizzazione a partire dal testo della issue.