Fix rare chat crash

.env

@@ -1,5 +1,5 @@
 API_ID=1025907
 API_HASH=452b0359b988148995f22ff0f4229750
 VERSION=1.5.0
-VERSION_FULL=1.5.0 (189)
+VERSION_FULL=1.5.0 (190)
-BUILD=189
+BUILD=190

src/components/chat/bubbles.ts

@@ -3165,7 +3165,9 @@ export default class ChatBubbles {
 
       this.ejectBubbles();
       for(const [bubble, oldBubble] of this.bubblesToReplace) {
+        if(scrollSaver) {
           scrollSaver.replaceSaved(oldBubble, bubble);
+        }
         
         if(!loadQueue.find((details) => details.bubble === bubble)) {
           continue;