Don't advance the main RNG during hallucination

This is based on the multiple-RNGs code fron NetHack4, but using
only the parts relevant to the display RNG (and with substantial
changes, both because of post-3.4.3 changes, and because Nethack4's
display code is based on Slash'EM's rather than NetHack's).

src/muse.c

@@ -1976,7 +1976,7 @@ struct monst *mtmp;
 #ifdef CLIPPING
     cliparound(mtmp->mx, mtmp->my);
 #endif
-    show_glyph(mtmp->mx, mtmp->my, mon_to_glyph(mtmp));
+    show_glyph(mtmp->mx, mtmp->my, mon_to_glyph(mtmp, rn2));
     display_self();
     You_feel("aggravated at %s.", noit_mon_nam(mtmp));
     display_nhwindow(WIN_MAP, TRUE);