In THT we allow RabbitAdditionalErlArgs to set some additional
parameters which should be passed to RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS
when starting rabbit. The problem is that when we use internal tls
that parameter gets ignored and so we lose our default '+sbwt none'.
Let's do this via a proper parameter while also considering the fact
that historically the default value of RabbitAdditionalErlArgs had
apices around it.
Since the original master change had an issue when the THT parameter
was unset (aka when I567839785a72813a382a00253562894e19eb6715 was not
applied to THT), we also add the subsequent fixup "Make the additional_erl_args
change more independent" I9fa9ba95410ed3994f608beb2c5e1578dc3a7c7a to
(cherry picked from commit