Take this test out of 'make check'. It's causing problems for a lot of people
due to fact that it's essentially a forkbomb. It's causing failures for Debian
on ARM and it's DoSing coredumps to system crash collectors.
The conditional only covers registration of the master, not the
subprocess parts. This is because g_test_slow() always return FALSE in
the subprocesses, so they would fail to run if we didn't register them
unconditionally.
30e1ab3262