fix #H1378 - vault guard interaction while swallowed

fix #H1378 - vault guard interaction while swallowed

     From a bug report, if you're swallowed
while in a vault and the guard arrives, he'll ask your name even though
you're hidden within the engulfer.  This makes him give a message and
then leave, as is already done if you're mimicking an object or unable to
speak.

     This also suppresses his repeated "Move along!" message if you're
swallowed or held since it's silly to keep telling you to move when you
obviously can't.