Removed the 'host:' prefix of the sample P4PORT value, to promote the
best pratice of using purely numeric P4PORT value for trigger and
broker scripts.
There's never reason for a server-side trigger (or broker) script to
specify the optional 'host:' portion of a P4PORT value, and in fact
doing so can be dangerous. Having a hard-coded 'host:' field makes it
all too easy for testing of triggers on a development server to
interact unwitingly with the live production server.