On LSP side we were only checking if ACCEPT_ZEROCONF_CHANNELS
is enabled while forwarding a non-trampoline htlc.
During trampoline forwarding the config was ignored.
The ACCEPT_* prefix implied this was only for accepting inbound
zeroconf channels, but it also controls whether we open them when
forwarding HTLCs.
Renames the config var to OPEN_ZEROCONF_CHANNELS
to clarify it enables zeroconf channel opens in both directions,
and add the missing check when forwarding trampoline HTLCs.
f321x
2da9fbbf15