lowercase keystone

src/hubspotConnector.js

@@ -51,7 +51,7 @@ let fields = {
         return targetCountry.toUpperCase();
     },*/
     corso_keystone: (lead) => lead.programList?.join('; ') ?? '',
-    leadsource: () => 'Keystone'
+    leadsource: () => 'keystone'
 };
 
 function mapFields(lead) {