vanilla: keymaster's locks still call givedice(d) when weakened, even though they become two needs x slots when weakened

[ncrecc]

givedice(d) for, say, an equipment with two needs3 slots (e.g. lock 3-), would give you back a 6

weakened keymaster locks should be specified manually with change_power and should return two dice whose value are the same and depends on the lock number

this could potentially be seen in normal gameplay with the wizard rule