Try to deactive SOL on logout

If we have an sol_handler, request SOL deactivation
on the way out.  This works around issues on select
codebases where IPMI stack state gets corrupt if a
payload is active during ipmi logout.

Change-Id: Ie1bcada6206c340bb954e5d5c8a99678e1d3162c

pyghmi/ipmi/private/session.py

@@ -1775,6 +1775,8 @@ class Session(object):
             return {'success': True}
         if self.cleaningup:
             self.nowait = True
+        if self.sol_handler:
+            self.raw_command(netfn=6, command=0x49, data=(1, 1, 0, 0, 0, 0))
         self.raw_command(command=0x3c,
                          netfn=6,
                          data=struct.unpack("4B",