twoweapon message adjustment

There was a concern that some things resulted in "is not a weapon"
when trying to twoweapon, then were subsequently refered to in
menus as "weapon in hand."

Remove any perceived inconsistency by simply adjusting the first
message.

src/wield.c

@@ -673,7 +673,8 @@ can_twoweapon()
     else if (NOT_WEAPON(uwep) || NOT_WEAPON(uswapwep)) {
         otmp = NOT_WEAPON(uwep) ? uwep : uswapwep;
         pline("%s %s.", Yname2(otmp),
-              is_plural(otmp) ? "aren't weapons" : "isn't a weapon");
+              is_plural(otmp) ? "aren't suitable weapons"
+                              : "isn't a suitable weapon");
     } else if (bimanual(uwep) || bimanual(uswapwep)) {
         otmp = bimanual(uwep) ? uwep : uswapwep;
         pline("%s isn't one-handed.", Yname2(otmp));