Fix fired iron ball sanity error

When hero was punished and swallowed, and fired the attached
iron ball from a quiver, thrownobj was not cleared.

doc/fixes36.3

@@ -178,6 +178,7 @@ avoid 'object lost' panic when polymorph causes loss of levitation boots or
 	wasn't possible to tell where they were, unlike all other forms of
 	multiple movement; stop running if/when an engraving is reached
 fix exploding land mine moving ball or chain and causing a sanity error
+fix firing attached iron ball when swallowed causing a sanity error
 
 
 Fixes to Post-3.6.2 Problems that Were Exposed Via git Repository

src/dothrow.c

@@ -1294,7 +1294,7 @@ boolean twoweap; /* used to restore twoweapon mode if wielded weapon returns */
                 || !index(in_rooms(mon->mx, mon->my, SHOPBASE), *u.ushops)))
             hot_pursuit(mon);
 
-        if (obj_gone)
+        if (obj_gone || obj == uball)
             thrownobj = (struct obj *) 0;
     }