Convert QmpMessage to a new-style class

Signed-off-by: Apollon Oikonomopoulos <apoikos@gmail.com>
Reviewed-by: Hrvoje Ribicic <riba@google.com>

lib/hypervisor/hv_kvm/monitor.py

@@ -35,7 +35,7 @@ from ganeti import utils
 from ganeti import serializer
 
 
-class QmpMessage:
+class QmpMessage(object):
   """QEMU Messaging Protocol (QMP) message.
 
   """