Provide reason when disconnecting a peer because they're slow

libbroker/broker/internal/core_actor.cc

@@ -873,7 +873,7 @@ caf::error core_actor_state::init_new_peer(endpoint_id peer_id,
       .on_backpressure_buffer(peer_buffer_size(), peer_overflow_policy())
       .do_on_error([this, ptr, peer_id](const caf::error& what) {
         BROKER_INFO("remove peer" << peer_id << "due to:" << what);
-        ptr->force_disconnect();
+        ptr->force_disconnect(to_string(what));
       })
       .as_observable());
   // Push messages received from the peer into the central merge point.