Allow specifying ports for transport maps

[deajan]

As the title suggests, some configurations need specific ports for transport maps.
Adding those via eFa-Configure is prohibited:

[Domain] : somedomain.tld
Thank you...

Now enter the destination server

[Destination] : 192.168.231.6:255
        ERROR: The value 192.168.231.6:255 seems to be invalid
        ERROR: please re-enter the destination

I modified /etc/postfix/transport to something like below and postmapped the file manually, which works for me

###### START eFa ADDED DOMAINS ######
domain.org  smtp:[192.168.231.6]:26
domain.fr  smtp:[192.168.231.6]:26

Also works on eFa-Configure

--------------------------------------------------------------
---        Welcome to the eFa Configuration program        ---
---               https://www.efa-project.org              ---
--------------------------------------------------------------


Description:
All mail domains for which this system accepts mail need an destination server.
Below is the list of current smtp mail domains on this system.

  1) domain.org            192.168.201.6:26
  2) domain.fr         192.168.201.6:2525

n) Add new mail domain

e) Return to main menu

[eFa] :

So basically the script would just need an adjustment to have an optional port.

Thank you.