[osx-issue] extend the thread workaround for MacOS X 10.9 for all minor versions.

Now the OS X 10.9.3 is released, we'll need to extend the hack.  Expecting we'll have 10.9.x (x>3) and the problem will stay, I've a bit generalized it.  Please review, or I'll just merge it myself as I believe this is
pretty trivial (and it worked for me).