Host mozilla.debian.net lacks proper SSL\TLS certificate

[Alexander V. Makartsev]

Hello.

I don't know if this is right place to send report, but it would be nice
to fix this problem.
I have successfully updated my apt source lists to https for quite some
time, and it looks like host debian.net lacks proper SSL\TLS certificate.

apt-get output:
=================
Err https://mozilla.debian.net jessie-backports/firefox-release amd64
Packages 
  SSL: certificate subject name (debian.org) does not match target host
name 'mozilla.debian.net'
Err https://mozilla.debian.net jessie-backports/firefox-release i386
Packages  
  SSL: certificate subject name (debian.org) does not match target host
name 'mozilla.debian.net'
Ign https://mozilla.debian.net jessie-backports/firefox-release
Translation-en_US
Ign https://mozilla.debian.net jessie-backports/firefox-release
Translation-en 
Fetched 494 kB in 11s (44,3
kB/s)                                              
W: Failed to fetch
https://mozilla.debian.net/dists/jessie-backports/firefox-release/binary-amd64/Packages 
SSL: certificate subject name (debian.org) does not match target host
name 'mozilla.debian.net'

W: Failed to fetch
https://mozilla.debian.net/dists/jessie-backports/firefox-release/binary-i386/Packages 
SSL: certificate subject name (debian.org) does not match target host
name 'mozilla.debian.net'

E: Some index files failed to download. They have been ignored, or old
ones used instead.
=================