Fix NBC iBarrier for inter-communicators.

Remove send of the extra message. This bug hase triggered on
MPICH/coll/nbicbarrier test. In this test a series of communicators
are created.
This extre-message was reseived after original communicator was destroyed
and queued into non_existing_communicator_pending. When new completely
unrelated communicator with the same id as original was created this message
was pushed into the frags_cant_match queue and caused seq numbers skew and hang.

ompi/mca/coll/libnbc/nbc_ibarrier.c

@@ -177,7 +177,7 @@ int ompi_coll_libnbc_ibarrier_inter(struct ompi_communicator_t *comm, ompi_reque
     }
 
     /* inform remote peers that all local peers have entered the barrier */
-    for (int peer = 0 ; peer < rsize ; ++peer) {
+    for (int peer = 1; peer < rsize ; ++peer) {
       res = NBC_Sched_send (0, true, 1, MPI_BYTE, peer, schedule, false);
       if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
         NBC_Return_handle (handle);