Unable to delete Log Shipping configuration
If something is still setup on the secondary server you need to run sp_delete_log_shipping_secondary_database there. 

You can clear the log shipping configuration on the primary by executing sp_delete_log_shipping_primary_secondary 

USE master;
GO
EXEC master.dbo.sp_delete_log_shipping_primary_secondary
    @primary_database = N'&lt;PrimaryDatabase&gt;'
   ,@secondary_server = N'&lt;SecondaryServer&gt;'
   ,@secondary_database = N'&lt;SecondaryDatabase&gt;'
GO