jsonrpc: Remove unecessary check

Change-Id: Ic1c04d3ba13b369c850370b9c5ffaf68da7328a7
Signed-off-by: Saggi Mizrahi <smizrahi@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/11623
Reviewed-by: Dan Kenigsberg <danken@redhat.com>
Tested-by: Dan Kenigsberg <danken@redhat.com>