Update warning to be specific to the **field** mapped to Bulk Upsert External Id

Author: bobbyatsegment

src/connections/destinations/catalog/actions-salesforce/index.md

@@ -167,4 +167,4 @@ For "Bulk Update Record ID", see [Salesforce’s help documentation](https://hel
 For "Bulk Upsert External ID", see [Salesforce’s help documentation](https://help.salesforce.com/s/articleView?id=000383278&type=1){:target="_blank"}.
 
 > warning ""
-> The **Bulk Upsert External Id** field should **not** be included in the Other Fields mapping. Including it as a custom field will cause an error in Salesforce. Although the Bulk API may return successful responses, the [Bulk Data Load Jobs](https://help.salesforce.com/s/articleView?id=sf.monitoring_async_api_jobs.htm&type=5) page in Salesforce will display error messages for failed operations.
+> The field mapped to Bulk Upsert External Id should **not** be included in the Other Fields mapping. Including it as a custom field will cause an error in Salesforce. Although the Bulk API may return successful responses, the [Bulk Data Load Jobs](https://help.salesforce.com/s/articleView?id=sf.monitoring_async_api_jobs.htm&type=5) page in Salesforce will display error messages for failed operations.