help browser: don't show production cost for non-buildable units
Even if unit is unbuildable, its value affects things like bribe cost, so it's not completely useless info.
Amend my request - Don't show production cost for units with both "NoBuild" and "Unbribable" flags.
No way to work around - all units have to have a line "build_cost=XXX", XXX has to be a number, 0 gets turned into 1, -1 turns into 65535.