ports-mgmt/synth: Upgrade version 1.51 => 1.52

Fix regression in text-mode caused by activation of watchdog.
The watchdog is checking the lengths of the build logs to figure out if
a builder has stalled. It turns out that the logs were only being
inspected in ncurses display mode, so any port that took longer than
20 minutes to build would be aborted by the watchdog.

While here, bump the *BASE* time limit for the build phase from 20 to
25 minutes based on extreme causes (normally involving gcc or tex ports)
and also bump the check-plist phase limit from 3 minutes to 10 minutes.
Some ports have tens of thousands of files in them which takes a long
time to check under test mode, especially if the server is loaded.