Symfony version(s) affected: 4.3

Description
After update to SF 4.3 apps with environment variables use in security config part stops working, because of this 857ac95

How to reproduce
Use env variable in security access control, for example:

security:
    ...
    access_control:
        - { path: '^/app', roles: IS_AUTHENTICATED_ANONYMOUSLY, ip: '%env(APP_IP)%' }

For versions below 4.3 it works as expected, on 4.3 exception is thrown:
The given "%env(APP_IP)%" value in the "access_control" config option is not a valid IP address.

Possible Solution
Do not validate env variables