Revert recent heredoc handling change for now
Revert recent heredoc handling change for now

Older libedit versions lack rl_set_prompt() and in some cases we ended
up with an empty prompt.

gquintard/Varnish-Cache,feld/Varnish-Cache,feld/Varnish-Cache,feld/Varnish-Cache,feld/Varnish-Cache,gquintard/Varnish-Cache,gquintard/Varnish-Cache,gquintard/Varnish-Cache,feld/Varnish-Cache