more issue #1253 - shape change vs Eleberth

I happened to restore a save file left over from testing yesterday's
attempt to fix github issue #1253 and had a werejackal change from
human to beast while next to my hero on "Elbereth", then attack me.

This should be sufficient to prevent that.  I'm not sure why the
previous fix attempt seemed to be adequate when testing it.  The new
fix relies on the previous one.

src/mhitu.c

@@ -671,7 +671,15 @@ mattacku(struct monst *mtmp)
        also, were creature might change from human to animal or vice versa */
     if (mtmp->cham == NON_PM && !mtmp->mcan && !range2
         && (is_demon(mdat) || is_were(mdat))) {
+        boolean already_fleeing = mtmp->mflee != 0;
+
         summonmu(mtmp, youseeit);
+        /* were-creature might have changed to beast form; if that has
+           caused it to become afraid (due to non-human reacting to scroll
+           of scare monster or engraved "Elbereth" which was being ignored
+           while in human form), don't continue this attack */
+        if (mtmp->mflee && !already_fleeing)
+            return 0;
         mdat = mtmp->data; /* update cached value in case of were change */
     }