Revert changes to monkey_patch.

Revert changes to monkey_patch.

As a work-around to deal with bug 1075838, we modified
monkey_patch in the Cinder binaries.  The root cause of the
issue is/was actually a bug in eventlet but this was a quick
work-around.

Since the change Change-Id: I69ba75136e32e95c6fdf108f0c4fe21a5e3bdbe6
to do this landed, the problem has also been addressed in Keystone.

So, let's revert this patch to get back the greenthread performance
that we may have lost with this change.  For now, everything should
be addressed as long as we don't implement multi api worker in Cinder,
if we do and the evenlet fix hasn't been released we'll need to turn
the modification back on for bin/cinder-api.

Change-Id: Ie845bade85dbceacd91f15e082325602d9a79c74