This commit uses the new coop-close-target-confs value as the default to
use for a nodes self initiated channel closures if the conf-target flag
for the channel closure is not set. The defaults for both these options
is 6 so this shouldnt change current behaviour.
This commit adds a new config option: "--coop-close-target-confs"
which allows a user to override the default target confirmations of 6
that is used to estimate a fee rate to use during a co-op closure
initiated by a remote peer.
Elle Mouton