Disable captive portal detection in Firefox.
(Maybe this change should be made in Geckodriver instead?)
"dom.max_script_run_time": 30,
"dom.report_all_js_exceptions": true,
"javascript.options.showInConsole": true,
+ "network.captive-portal-service.enabled": false,
"security.csp.enable": false,
"startup.homepage_welcome_url": "about:blank",
"startup.homepage_welcome_url.additional": "about:blank",
