Fix another bug in previous commits.

Something weird happened during startup where perhaps the event queue
was not yet initialized in a way that satisfies the usual invariant that
it contains no events in the past. I did not take the time to
investigate this in sufficient depth to say more.

core/federated/federate.c

@@ -2742,12 +2742,11 @@ tag_t _lf_send_next_event_tag(environment_t* env, tag_t tag, bool wait_for_reply
                     lf_print_error("Wait error.");
                 }
                 // Check whether the new event on the event queue requires sending a new NET.
-                tag_t next_tag = get_next_event_tag(env);
-                if (
-                    lf_tag_compare(_fed.last_TAG, next_tag) >= 0
-                    || lf_tag_compare(_fed.last_TAG, tag) >= 0
-                ) {
-                    return _fed.last_TAG;
+                if (lf_tag_compare(_fed.last_TAG, tag) >= 0) {
+                    tag_t next_tag = get_next_event_tag(env);
+                    if (lf_tag_compare(_fed.last_TAG, next_tag) >= 0) {
+                        return _fed.last_TAG;
+                    }
                 }
                 if (lf_tag_compare(next_tag, tag) != 0) {
                     _lf_send_tag(MSG_TYPE_NEXT_EVENT_TAG, next_tag, wait_for_reply);