python-greenlet: uprev to 0.4.1

During runtime testing of meta-cloud-services several python scripts were
continunously segfaulting the interpreter. corefiles and gdb pointed at
the greenlet implementation.

Moving to 0.4.1 fixed the segfaults, and showed no regressions.

Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>