run-tests: don't mask errors when a server fails to start There are sporadic instances of this on Windows. They seem to happen more frequently after the test machine is rebooted, although the only way to hit it on my laptop is to loop certain tests with -j9 for hours. The problem with masking out the specific failure is that there's no way to know if it's the same line in the test that's failing, or if it is random. The justification for adding this masking in 52e9e63f1495 was that the failures occur regularly, but that's not the case anymore. The port number is still printed, in case that turns out to be useful.