bitbake: bin/bitbake: Catch establish connection log messages

If for example you try "bitbake -m" with an invalid BBSERVER, error
messages are not displayed. This change ensures logging is in place
to catch and display such errors.

(Bitbake rev: 719808f95adc7820fcc09743c592513414d03ce1)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>