B04002 fix for misplaced pet loyalty

B04002 fix for misplaced pet loyalty

<Someone> wrote:
>This _must_ be a bug: if a character leaves a pet corpse in a
>bonesfile, someone getting those bones will receive
>"So this is how you repay loyalty?"  should he sacrifice it, even
>though the loyalty wasn't shown to _him_."

Clear the appropriate fields from the attached monst structure
when loading bones.