Fix test case weirdness

Line 23 clearly shows that the click is taking effect. Only
the property change isn't being applied.

Author: notriddle

tests/rustdoc-gui/sidebar-resize-setting.goml

@@ -21,4 +21,3 @@ wait-for-css: ("#settings", {"display": "block"})
 assert-property: ("#hide-sidebar", {"checked": "true"})
 click: "#hide-sidebar"
 wait-for-css: (".sidebar", {"display": "block"})
-assert-property: ("#hide-sidebar", {"checked": "false"})