firefox regression

USN-4717-1 fixed vulnerabilities in Firefox. The update caused a
startup hang in some circumstances. This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

Multiple security issues were discovered in Firefox. If a user were
tricked in to opening a specially crafted website, an attacker could
potentially exploit these to cause a denial of service, obtain sensitive
information, conduct clickjacking attacks, or execute arbitrary code.