fix #H4146 - more enlightenment vs drain resistance

Duplicate of another recent report as far as drain resistance from
Excalibur/Stormbringer/Staff of Aesculapius not being shown by
enlightenment goes, but this one mentioned that it also wasn't being
shown for lycanthropy.  Being inflicted by that does confers level-
drain resistance.  were_change() wasn't calling set_uasmon() since
it isn't changing youmonst.data, but set_uasmon() is were intrinsics
conferred by creature form are set up.  So call it when changing
were-form.  Direct access to u.ulycn wasn't calling it either, so add
a new routine to assign the value to that instead doing so directly.

src/mhitu.c

@@ -1248,7 +1248,7 @@ register struct attack *mattk;
             && !Protection_from_shape_changers && !defends(AD_WERE, uwep)) {
             You_feel("feverish.");
             exercise(A_CON, FALSE);
-            u.ulycn = monsndx(mdat);
+            set_ulycn(monsndx(mdat));
             retouch_equipment(2);
         }
         break;