fix(sdk): Fix logic if read marker event was not in the timeline

crates/matrix-sdk/src/room/timeline/event_handler.rs

@@ -277,6 +277,7 @@ fn update_fully_read_item(
             *fully_read_event_in_timeline = false;
         }
         (Some(from), Some(to)) => {
+            *fully_read_event_in_timeline = true;
             items_lock.move_from_to(from, to);
         }
     }