Changed sales_order_save_after observer's name

etc/events.xml

@@ -12,7 +12,7 @@
 -->
 <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
     <event name="sales_order_save_after">
-        <observer name="mailchimp_admin_sales_order_save_after" instance="\Ebizmarts\MailChimp\Observer\Sales\Order\SaveAfter"/>
+        <observer name="mailchimp_sales_order_save_after" instance="\Ebizmarts\MailChimp\Observer\Sales\Order\SaveAfter"/>
     </event>
     <event name="sales_model_service_quote_submit_before">
         <observer name="mailchimp_sales_model_service_quote_submit_before" instance="\Ebizmarts\MailChimp\Observer\Sales\Order\SubmitBefore" />