firefox-esr-60: 60.2.2 -> 60.3.0 [critical security fixes]

This update bumps the package to the latest stable version containing a
few security fixes:

- CVE-2018-12392: Crash with nested event loops
  When manipulating user events in nested loops while opening a document
  through script, it is possible to trigger a potentially exploitable
  crash due to poor event handling.

- CVE-2018-12393: Integer overflow during Unicode conversion while loading JavaScript
  A potential vulnerability was found in 32-bit builds where an integer
  overflow during the conversion of scripts to an internal UTF-16
  representation could result in allocating a buffer too small for the
  conversion. This leads to a possible out-of-bounds write.
  Note: 64-bit builds are not vulnerable to this issue.

- CVE-2018-12395: WebExtension bypass of domain restrictions through header rewriting
  By rewriting the Host request headers using the webRequest API, a
  WebExtension can bypass domain restrictions through domain fronting.
  This would allow access to domains that share a host that are
  otherwise restricted.

- CVE-2018-12396: WebExtension content scripts can execute in disallowed contexts
  A vulnerability where a WebExtension can run content scripts in
  disallowed contexts following navigation or other events. This allows
  for potential privilege escalation by the WebExtension on sites where
  content scripts should not be run.

- CVE-2018-12397: Missing warning prompt when WebExtension requests local file access
  A WebExtension can request access to local files without the warning
  prompt stating that the extension will "Access your data for all
  websites" being displayed to the user. This allows extensions to run
  content scripts in local pages without permission warnings when a
  local file is opened.

- CVE-2018-12389: Memory safety bugs fixed in Firefox ESR 60.3
  Mozilla developers and community members Daniel Veditz and Philipp
  reported memory safety bugs present in Firefox ESR 60.2. Some of these
  bugs showed evidence of memory corruption and we presume that with
  enough effort that some of these could be exploited to run arbitrary
  code.

- CVE-2018-12390: Memory safety bugs fixed in Firefox 63 and Firefox ESR 60.3
  Mozilla developers and community members Christian Holler, Bob Owen,
  Boris Zbarsky, Calixte Denizet, Jason Kratzer, Jed Davis, Taegeon Lee,
  Philipp, Ronald Crane, Raul Gurzau, Gary Kwong, Tyson Smith, Raymond
  Forbes, and Bogdan Tara reported memory safety bugs present in Firefox
  62 and Firefox ESR 60.2. Some of these bugs showed evidence of memory
  corruption and we presume that with enough effort that some of these
  could be exploited to run arbitrary code.

Source: https://www.mozilla.org/en-US/security/advisories/mfsa2018-27/