Проблема с понижением nginx - не может удалить зависимости

Мне нужно понизить nginx с 1.10.1 до 1.4.6. Однако я застрял. Пожалуйста, посмотрите ниже:

root@FServer:~# nginx -v
nginx version: nginx/1.10.1
root@FServer:~# apt-cache policy nginx
nginx:
  Installed: 1:1.10.1-8.5.0.29~trusty1
  Candidate: 1:1.10.1-8.5.0.29~trusty1
  Version table:
 *** 1.10.1-0+trusty0 0
        500 http://ppa.launchpad.net/nginx/stable/ubuntu/ trusty/main amd64 Packages
     1.4.6-1ubuntu3.5 0
        500 http://mirrors.digitalocean.com/ubuntu/ trusty-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages
root@FServer:~# apt-get remove --auto-remove nginx
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages will be REMOVED:
  nginx
0 upgraded, 0 newly installed, 1 to remove and 388 not upgraded.
After this operation, 55.3 kB disk space will be freed.
Do you want to continue? [Y/n] Y
(Reading database ... 125312 files and directories currently installed.)
Removing nginx (1:1.10.1-8.5.0.29~trusty1) ...
root@FabServer:~# sudo apt-get install nginx=1.4.6-1ubuntu3
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 nginx : Depends: nginx-core (< 1.4.6-1ubuntu3.1~) but 1:1.10.1-8.5.0.29~trusty1 is to be installed or
                  nginx-full (< 1.4.6-1ubuntu3.1~) but 1:1.10.1-8.5.0.29~trusty1 is to be installed or
                  nginx-light (< 1.4.6-1ubuntu3.1~) but 1:1.10.1-8.5.0.29~trusty1 is to be installed or
                  nginx-extras (< 1.4.6-1ubuntu3.1~) but 1:1.10.1-8.5.0.29~trusty1 is to be installed or
                  nginx-naxsi (< 1.4.6-1ubuntu3.1~) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

root@FServer:~# apt-get remove --auto-remove nginx-core
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package 'nginx-core' is not installed, so not removed
0 upgraded, 0 newly installed, 0 to remove and 388 not upgraded.

Итак, у меня странная ситуация - формальный пакет nginx не имеет зависимостей при удалении, но имеет его при установке. Кроме того, я не могу удалить пакеты, такие как система nginx-core, думаю, что она не установлена.

Что вы можете порекомендовать?