Update tooltip for multi-user mode

Closes #6333

bigbluebutton-html5/private/locales/en.json

@@ -456,8 +456,8 @@
     "app.whiteboard.toolbar.color.silver": "Silver",
     "app.whiteboard.toolbar.undo": "Undo annotation",
     "app.whiteboard.toolbar.clear": "Clear all annotations",
-    "app.whiteboard.toolbar.multiUserOn": "Turn multi-user mode on",
-    "app.whiteboard.toolbar.multiUserOff": "Turn multi-user mode off",
+    "app.whiteboard.toolbar.multiUserOn": "Turn multi-user whiteboard on",
+    "app.whiteboard.toolbar.multiUserOff": "Turn multi-user whiteboard off",
     "app.whiteboard.toolbar.fontSize": "Font Size List",
     "app.feedback.title": "You have logged out of the conference",
     "app.feedback.subtitle": "We'd love to hear about your experience with BigBlueButton (optional)",