Web platform test server should not try to launch servers on already bound sockets

Web platform test server should not try to launch servers on already bound sockets
https://bugs.webkit.org/show_bug.cgi?id=141157

Reviewed by Darin Adler.

LayoutTests/imported/w3c:

* resources/config.json: Changed wpt https port from 8443 to 9443.
* web-platform-tests/fetch/api/basic/mode-no-cors-expected.txt: Updated according https port change.
* web-platform-tests/fetch/api/basic/mode-no-cors-worker-expected.txt: Ditto.
* web-platform-tests/fetch/api/basic/mode-same-origin-expected.txt: Ditto.
* web-platform-tests/fetch/api/basic/mode-same-origin-worker-expected.txt: Ditto.

Tools:

* Scripts/webkitpy/layout_tests/servers/web_platform_test_server.py:
(wpt_config_json): Load WPT config from LayoutTests/imported/w3c/resources/config.json.
(base_url): Refactored to use wpt_config_json routine.
(WebPlatformTestServer.__init__): Fill port mappings according WPT config.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@198116 268f45cc-cd09-0410-ab3c-d52691b4dbfc