Adjust seams on rudder gusset channel

Hole mismatch of up to 1.6mm between RD-CHL-002 and skins was traced to slightly incorrect seams in the former. The 90 degree seam was opened out and recreated about 1.5mm closer to the spar channel holes. The 30 degree seam was opened out and recreated about 1.6/tan(30 degrees) ~ 2.0 mm closer to the lightening hole.