Updated firefox packages fix security vulnerabilities

Mozilla developer Jason Kratzer reported memory safety bugs present in Firefox ESR 78.2. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code (CVE-2020-15673). Firefox sometimes ran the onload handler for SVG elements that the DOM sanitizer decided to remove, resulting in a XSS issue due to JavaScript being executed after pasting attacker-controlled data into a contenteditable element (CVE-2020-15676). By exploiting an Open Redirect vulnerability on a website, an attacker could have spoofed the site displayed in the download file dialog to show the original site (the one suffering from the open redirect) rather than the site the file was actually downloaded from (CVE-2020-15677). When recursing through graphical layers while scrolling, an iterator may have become invalid, resulting in a potential use-after-free. This occurs because the function APZCTreeManager::ComputeClippedCompositionBounds did not follow iterator invalidation rules (CVE-2020-15678). The firefox package has been updated to the 78.x ESR branch, which brings significant changes in how CA certificates and smart cards are loaded into Firefox. The root CA certificates are no longer statically built into the nss library. They are loaded dynamically via p11-kit-trust, and therefore may be modified by the system administrator. Smart card support should be automatically loaded via p11-kit-trust as well, rather than requiring opensc to be manually loaded. NSS also now complies with the system crypto policy, which is provided by the crypto-policies package. See the fedoraproject references for details.