Correct the duplicated article in the static openchannel
help text so the command summary reads cleanly. Refresh the
recorded help fixtures that surface that summary directly,
including the dedicated openchannel help output and the
parent static command listing.
Also fix --sat_per_vbyte flag.
All these flags were accessed using wrong type (signed vs unsigned int).
Previous version always parsed them as 0 even when set.
Regenerate the manual.