Remove tst_setUrlWithFragment test case

This test is flaky, we don't have proper signals for in-page
navigations and this case tests the behavior of the browser
engine, not the QtWebEngine API.

Change-Id: Ia94219df3501126bf1ab00a400a57d589b651589
Reviewed-by: Andras Becsi <andras.becsi@theqtcompany.com>