[docker] remove unused arguments from Docker entrypoint (#1232)
[docker] remove unused arguments from Docker entrypoint (#1232)

Both, --disable-default-prefix-route and --disable-default-prefix-slaac
have been used for wpantund which is no longer supported by the Docker
entrypoint script. Remove them to avoid confusion.
openthread/ot-br-posix,openthread/borderrouter,openthread/ot-br-posix,openthread/ot-br-posix,openthread/borderrouter,openthread/borderrouter,openthread/ot-br-posix,openthread/borderrouter,openthread/ot-br-posix,openthread/ot-br-posix,openthread/borderrouter,openthread/borderrouter