Updated webkit2 packages fix security vulnerability

webkit2 packages have been updated to 2.26.4 and fixed the followin security vulnerabilities: A malicious website may be able to cause a denial of service (CVE-2020-3862). A DOM object context may not have had a unique security origin (CVE-2020-3864). A top-level DOM object context may have incorrectly been considered secure (CVE-2020-3865). Processing maliciously crafted web content may lead to universal cross site scripting (CVE-2020-3867). Processing maliciously crafted web content may lead to arbitrary code execution (CVE-2020-3868).