tests: Mark JsonRpcServerTests as broken

Change-Id: I351ab7d45c980616199e2b4025cba74905cb25e2
Signed-off-by: Yeela Kaplan <ykaplan@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/16327
Reviewed-by: Dan Kenigsberg <danken@redhat.com>
Tested-by: Dan Kenigsberg <danken@redhat.com>