Fix/tweak the jewellery_prompt option (rypofalem)

It was still skipping the prompt when the player tried to put on a ring
while their ring slots were full of identical rings. It should now prompt
here, as expected.

However, some of the original behavior of this option is difficult to
preserve. There *isn't* any concept of 'different ring slots' anymore to
force the player to choose from when multiple are empty. So, I have edited
the option description to no longer say that it does anything in this case.

Author: DracoOmega

crawl-ref/docs/options_guide.txt

@@ -1163,11 +1163,10 @@ equip_unequip = true
         respectively) will unequip that item.
 
 jewellery_prompt = false
-        If this is true, equipping rings will always prompt for the slot to
-        use, instead of automatically equipping the ring if there is an
-        available empty slot. Unequipping jewellery will also always prompt for
-        an item to remove, instead of skipping the prompt if only one item
-        of jewellery is equipped.
+        If this is true, unequipping jewellery will always prompt for an item
+        to remove, instead of skipping the prompt if only one item of jewellery
+        is equipped. Also, if all slots are filled when equipping a jewellery
+        item, it will prompt for which you remove even if they are all identical.
 
 easy_confirm = (none | safe | all)
         Make confirmation questions easier to answer:

crawl-ref/source/item-use.cc

@@ -1144,11 +1144,16 @@ static item_def* _item_swap_prompt(const vector<item_def*>& candidates)
     // If our list contains only identical items, return the first without a
     // prompt.
     bool found_non_match = false;
-    for (size_t i = 0; i < candidates.size() - 1; ++i)
+    for (size_t i = 0; i < candidates.size(); ++i)
     {
         item_def* item = candidates[i];
+
+        // If this option is true, all jewellery is considered 'non-matching'
         if (item->base_type == OBJ_JEWELLERY && Options.jewellery_prompt)
-            continue;
+        {
+            found_non_match = true;
+            break;
+        }
 
         for (size_t j = i + 1; j < candidates.size(); ++j)
         {
@@ -1389,19 +1394,7 @@ bool try_equip_item(item_def& item)
             }
 
             if (candidates.size() == 1)
-            {
-                if (item.base_type == OBJ_JEWELLERY && Options.jewellery_prompt)
-                {
-                    item_def* ret = _item_swap_prompt(candidates);
-
-                    if (ret)
-                        to_remove.push_back(ret);
-                    else
-                        return false;
-                }
-                else
-                    to_remove.push_back(candidates[0]);
-            }
+                to_remove.push_back(candidates[0]);
             else
             {
                 // Save which item was selected to remove.