Unbreak nightly build

Unbreak nightly build

The nightly build uses a gross hack to keep timestamps stable: it
replaces the system's time() by emp_time().  It doesn't replace other
time-related functions such as gettimeofday().  Works as long as we
don't mix hacked time with unhacked time.

The previous commit compares time gotten from gettimeofday() with time
gotten from time().  The nightly build's I/O timeouts become zero,
which makes login impossible.

Replace gettimeofday(), too.