Masterbar: display a pointer cursor for the sidebar menu toggle button

Author: ciampo

client/layout/masterbar/style.scss

@@ -562,6 +562,7 @@ body.is-mobile-app-view {
 			display: inline-block;
 			margin-right: 2px;
 			margin-left: -1px;
+			cursor: pointer;
 		}
 	}