Investigate the current security status of Icedove + NSS as shipped in Tails 1.7 & 1.8

See

• https://security-tracker.debian.org/tracker/source-package/nss
• https://security-tracker.debian.org/tracker/source-package/icedove

and report back.

Parent Task: #5663 (closed)

Original created by @u on 10752 (Redmine)