In ports.cgi, when indexing the INDEX file, track what we have found by
using the port origin rather than the link to the port pkg-descr.  For
ports which are sub-ports of others (e.g. most pf te php5* ports) all
would have the same pkg-descr listed in the index and so we would only
show the last-found port, rather than all matching ports.

Reported by:	Can0r <can0r yandex ru> via -doc