make sure there is a hydrate event before we assume

if the app is stateless, then presumably we don't end up connecting a websocket
at all, so we wouldn't hit this code. also if `initialEvents` was empty for
whatever reason, then the app probably wouldn't work... but lets make it look a
bit safer.

Author: masenf

reflex/.templates/web/utils/state.js

@@ -618,16 +618,19 @@ export const connect = async (
     window.addEventListener("unload", disconnectTrigger);
     if (socket.current.rehydrate) {
       socket.current.rehydrate = false;
-      // On reconnect, we only hydrate, do not re-run on_load events.
-      const hydrate_event = initialEvents()[0];
-      hydrate_event.payload.is_reconnect = true;
-      queueEvents(
-        [hydrate_event],
-        socket,
-        true,
-        navigate,
-        () => params.current,
-      );
+      const events = initialEvents();
+      if (events.length > 0) {
+        // On reconnect, we only hydrate, do not re-run on_load events.
+        const hydrate_event = initialEvents()[0];
+        hydrate_event.payload.is_reconnect = true;
+        queueEvents(
+          [hydrate_event],
+          socket,
+          true,
+          navigate,
+          () => params.current,
+        );
+      }
     }
     // Drain any initial events from the queue.
     while (event_queue.length > 0 && !event_processing) {