ref(toolbar): change tooltip prop name to stop deprecation warning (#3186)

react/features/base/toolbox/components/ToolboxItem.web.js

         if (useTooltip) {
             return (
                 <Tooltip
-                    description = { tooltip }
+                    content = { tooltip }
                     position = { tooltipPosition }>
                     { iconWrapper }
                 </Tooltip>