Small fix for label selection box

Author: lumburovskalina

src/components/projects/projectId/labeling/sessionId/sub-components/LabelingSuiteLabeling.tsx

@@ -517,11 +517,10 @@ export default function LabelingSuiteLabeling() {
 
     function handleKeyboardEvent(event) {
         const labelSelection = document.getElementById('label-selection-box');
-        if (!labelSelection) return;
         if (event.key == 'ArrowRight' || event.key == 'ArrowLeft') {
             setActiveTasksFunc([]);
         }
-        if (!labelSelection.classList.contains('hidden')) return;
+        if (labelSelection && !labelSelection.classList.contains('hidden')) return;
         for (const key in labelHotkeys) {
             if (key == event.key) {
                 const task = labelingTasks.find(t => t.id == labelHotkeys[key].taskId);