Monkey patch threading module as early as possible

In oslo.messaging, local thread store is used to pass RPC request
context [1]. If we try to import oslo.messaging before monkey patching
threading library, it attempts to access unpatched storage and fails
with AttributeError.

[1]: oslo/messaging/localcontext.py#L26

blueprint oslo-messaging

Change-Id: Ied7302fcb1d3e14428540e39e3db704550027890
Merge "Monkey patch threading module as early as possible"