Port dropdowns: Put port no. after descrip

At the moment, even if a port number is entered, it's re-displayed only as a port name when editing. Users who don't have port names -> numbers lookup memorised can't easily confirm when editing a rule, that the port is as intended. Then, when they return to firewall_rules.php the same rules have ports displayed as numbers not names (inconsistent).

This small UI edit changes the port dropdowns from just the name "NetBIOS-NS" to "NetBIOS-NS (137)" and shows the very well known port number, for ease of use.
Merge pull request #975 from stilez/patch-1

Port dropdowns: Put port no. after descrip