compute rpcapi 2.37 is not backwards compatible

Patch 552693e4ad51291c8bfd28cd1939ed3609f6eeac which added compute
rpcapi version 2.37 does not provide any backwards compatibility.

Fix the issue by 'self.can_send_version'.

Fix bug 1217044

Change-Id: I65154fa6298133721b6509b00b117d7f6cc455b8
Merge "compute rpcapi 2.37 is not backwards compatible"