jsonrpc: Accept all stomp commands

Protocol detector needs to accept all stomp commands. The connection can
be lost at any time with the engine so we need to make sure that we
still accept incoming connections from the engine.

Bug-Url: https://bugzilla.redhat.com/1115044
Change-Id: I63029e43bfd5f06bb8f25958b78f75850d45b6df
Signed-off-by: pkliczewski <piotr.kliczewski@gmail.com>
Reviewed-on: http://gerrit.ovirt.org/29652
Reviewed-by: Nir Soffer <nsoffer@redhat.com>
Reviewed-by: Oved Ourfali <oourfali@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>