The capability was added in commit 58868b7, but since then, the USER
instruction was removed from the Dockerfile, so that Adguard Home runs
as root by default.
Even if it is run as non-root user, the capability is not required in
docker versions >= 20.10.0 (released on Dec 9, 2020), because of commit
888da28[1], which sets `net.ipv4.ip_unprivileged_port_start` to `0` by
default. Users running older docker versions or using the `host` network
mode can still configure this sysctl manually.
[1] 888da28d42
9ef9ccaf23