fix issue #843 - vampire revival sequencing

Reported by Umbire:
|You kill SpaceMannSpiff!  SpaceMannSpiff puts on a dwarvish cloak.
|SpaceMannSpiff puts on a dwarvish iron helm.
|The seemingly dead SpaceMannSpiff suddenly transforms and rises as
| a Vampire.

This was tough to reproduce but I finally managed it.  The issue
text mentions that it was fixed by copperwater in xNetHack with
commit 8c4af50f0aa3e72522f3eb98df039ff25c2a1ea0 to the repository
for that variant.  My attempt to cherry-pick that failed--I'm not
even sure whether it should have been expected to work--and some of
the code has been impinged upon by changes, so I ended up applying
the contents of that commit manually.

The commit changes how/when monsters put on new armor rather than
anything directly related to vampires.  Circumstances similar to
the example above now yield:
|You kill SpaceMannSpiff!
|The seemingly dead SpaceMannSpiff suddenly transforms and rises as
| a Vampire.
on one turn, then on the next turn the revived vampire produces:
|SpaceMannSpiff puts on a dwarvish cloak.

My test case only had one item of interest; I assume that the second
item of armor gets worn on a subsequent turn rather than at the same
time as the first one.

Fixes #843

src/worn.c

@@ -1145,7 +1145,7 @@ extract_from_minvent(
         mon->misc_worn_check &= ~unwornmask;
         /* give monster a chance to wear other equipment on its next
            move instead of waiting until it picks something up */
-        mon->misc_worn_check |= I_SPECIAL;
+        check_gear_next_turn(mon);
     }
     obj_no_longer_held(obj);
     if (unwornmask & W_WEP) {