(merge 3.2) Issue #12363: increase the timeout of siginterrupt() tests
(merge 3.2) Issue #12363: increase the timeout of siginterrupt() tests

Move also the "ready" trigger after the installation of the signal handler and
the call to siginterrupt().

Use a timeout of 5 seconds instead of 3. Two seconds are supposed to be enough,
but some of our buildbots are really slow (especially the FreeBSD 6 VM).

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator