wishing fix for "eyes"

No, not a blindness cure. :-}  Post-3.4.3 revisions to makesingular()
inadvertently made it impossible to successfully wish for "the Eyes
of the Overworld" because the string got changed into "the Eye of the
Overworld" which doesn't match anything.  So don't singularize "eyes".

(After this fix, wishing for "the Eyes of the Aethiopica" no longer
yields the Eye of same, but I think that's the correct behavior.)

src/objnam.c

@@ -1,4 +1,4 @@
-/* NetHack 3.5	objnam.c	$NHDT-Date$  $NHDT-Branch$:$NHDT-Revision$ */
+/* NetHack 3.5	objnam.c	$NHDT-Date: 1426977394 2015/03/21 22:36:34 $  $NHDT-Branch: master $:$NHDT-Revision: 1.108 $ */
 /* NetHack 3.5	objnam.c	$Date: 2011/10/27 02:24:54 $  $Revision: 1.101 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -1682,7 +1682,7 @@ static struct sing_plur one_off[] = {
 static const char *const as_is[] = {
 	/* makesingular() leaves these plural due to how they're used */
 	"boots", "shoes",
-	"gloves", "lenses", "scales",
+	"gloves", "lenses", "scales", "eyes",
 	"gauntlets",
 	"iron bars",
 	/* both singular and plural are spelled the same */