MAGETWO-75394: Deliver backport to 2.1

Author: kandy

app/code/Magento/Catalog/etc/events.xml

@@ -57,7 +57,4 @@
     <event name="admin_system_config_changed_section_catalog">
         <observer name="catalog_update_price_attribute" instance="Magento\Catalog\Observer\SwitchPriceAttributeScopeOnConfigChange" />
     </event>
-    <event name="catalog_product_save_before">
-        <observer name="set_special_price_start_date" instance="Magento\Catalog\Observer\SetSpecialPriceStartDate" />
-    </event>
 </config>