Remove support for datetime as date with null time
This exception was added by 9a9c2ca4f507 to support XML-RPC but since 074724027ac6 we use a dedicated structure for date in XML-RPC.
This exception was added by 9a9c2ca4f507 to support XML-RPC but since 074724027ac6 we use a dedicated structure for date in XML-RPC.