Merge pull request #20026 from Arthurk12/bbb/2.7/multiuser-non-presenter-error

fix(whiteboard): check before manipulating pan tool class list

bigbluebutton-html5/imports/ui/components/whiteboard/component.jsx

@@ -145,9 +145,12 @@ export default function Whiteboard(props) {
     } else {
       setIsPanning(false);
       setPanSelected(false);
+      if (panButton) {
+        // only presenter has the pan button
         panButton.classList.add('selectOverride');
         panButton.classList.remove('select');
       }
+    }
   };
 
   const setDockPosition = (setSetting) => {