Update legacy firefox36 package to 3.6.21.
Fixes some security issues:

MFSA 2011-34 Protection against fraudulent DigiNotar certificates
MFSA 2011-30 Security issues addressed in Firefox 3.6.20
MFSA 2011-24 Cookie isolation error
MFSA 2011-23 Multiple dangling pointer vulnerabilities
MFSA 2011-22 Integer overflow and arbitrary code execution in Array.reduceRight()
MFSA 2011-21 Memory corruption due to multipart/x-mixed-replace images
MFSA 2011-20 Use-after-free vulnerability when viewing XUL document with script disabled
MFSA 2011-19 Miscellaneous memory safety hazards (rv:3.0/1.9.2.18)

(tnn)