CCBC-1669: fail get_all_replicas only if none nodes are available

Change-Id: I760304753d3db329fdba3993aa0618ba22e1ddac
Reviewed-on: https://review.couchbase.org/c/libcouchbase/+/232446
Tested-by: Build Bot <build@couchbase.com>
Reviewed-by: Jared Casey <jared.casey@couchbase.com>

Author: avsej

src/operations/get_replica.cc

@@ -294,9 +294,6 @@ static std::vector<readable_node> select_effective_node_indexes(lcb_INSTANCE *in
     for (std::size_t ii = 0; ii < LCBT_NREPLICAS(instance); ii++) {
         int node_index = lcbvb_vbreplica(cq->config, vbid, ii);
         if (node_index < 0) {
-            if (cmd->mode() == get_replica_mode::all) {
-                return {};
-            }
             continue;
         }
         if (use_preferred_server_group) {