jsonrpc: Change cxtr to connector to make the code a bit more understandable

Change-Id: I39846bca542e84ee792a367789d39facd9e90c25
Signed-off-by: Saggi Mizrahi <smizrahi@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/10631
Reviewed-by: Adam Litke <agl@us.ibm.com>
Tested-by: Adam Litke <agl@us.ibm.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>