I can not get php7 after adding ppa: ondrej / php

I added the repository by this command:

WARNING: add-apt-repository breaks with regional settings that are not UTF-8, see
https://github.com/oerdnj/deb.sury.org/issues/56 for the solution:

More information: https://launchpad.net/~ondrej/+archive/ubuntu/php
press [ENTER] to continue or ctrl-c to cancel add it

gpg: keychain /tmp/tmph7kev8sf/secring.gpg & # 39; created
gpg: keychain
/tmp/tmph7kev8sf/pubring.gpg & # 39; created
gpg: requesting the key E5267A6C from the server hkp keyserver.ubuntu.com
gpg: /tmp/tmph7kev8sf/trustdb.gpg: trustdb created
gpg: key E5267A6C: public key "Launchpad PPA for Ondřej Surý" imported
gpg: Total number processed: 1
gpg: imported: 1 (RSA: 1)
IN AGREEMENT

everything looks good then I run apt-cache

what does not give anything

This is my system information:
~ # uname -a
Linux cspweb 3.13.0-123-generic # 172-Ubuntu SMP Mon June 26 18:04:35 UTC 2017 x86_64 x86_64 x86_64 GNU / Linux

place
LANG = en_US.UTF-8
LANGUAGE =
LC_CTYPE = "en_US.UTF-8"
LC_NUMERIC = "en_US.UTF-8"
LC_TIME = "en_US.UTF-8"
LC_COLLATE = "en_US.UTF-8"
LC_MONETARY = "en_US.UTF-8"
LC_MESSAGES = "en_US.UTF-8"
LC_PAPER = "en_US.UTF-8"
LC_NAME = "en_US.UTF-8"
LC_ADDRESS = "en_US.UTF-8"
LC_TELEPHONE = "en_US.UTF-8"
LC_MEASUREMENT = "en_US.UTF-8"
LC_IDENTIFICATION = "en_US.UTF-8"
LC_ALL =

I even try LC_ALL = C.UTF-8 add-apt-repository to ppa: ondrej / php, the same result. Any suggestions and suggestions are greatly appreciated.