MAGETWO-67010: [Performance] Swatches real server side optimization

- optimize tier price load

Author: mslabko

app/code/Magento/Bundle/Observer/LoadProductOptionsObserver.php

@@ -9,9 +9,6 @@
     <event name="catalog_product_upsell">
         <observer name="bundle_observer" instance="Magento\Bundle\Observer\AppendUpsellProductsObserver"/>
     </event>
-    <event name="catalog_product_collection_load_after">
-        <observer name="bundle_observer" instance="Magento\Bundle\Observer\LoadProductOptionsObserver"/>
-    </event>
     <event name="product_option_renderer_init">
         <observer name="bundle_observer" instance="Magento\Bundle\Observer\InitOptionRendererObserver"/>
     </event>

app/code/Magento/Bundle/etc/frontend/events.xml

@@ -2175,9 +2175,7 @@ private function fillTierPriceData(\Magento\Framework\DB\Select $select)
         }
         foreach ($this->getItems() as $item) {
             $productId = $item->getData($this->getLinkField());
-            if (isset($tierPrices[$productId])) {
-                $this->getBackend()->setPriceData($item, $tierPrices[$productId]);
-            }
+            $this->getBackend()->setPriceData($item, isset($tierPrices[$productId]) ? $tierPrices[$productId] : []);
         }
     }