pdb_xlog init fails when Microsoft SQL Server 2005 is upgraded to the developer version

[CR #539151] pdb_xlog init fails when a SQL Server instance is upgraded from Microsoft SQL Server 2005 standard version to the developer version. This is a limitation of Microsoft SQL Server itself: during SQL Server upgrading, the “Agent XPs” component is turned off, which prevents pdb_xlog init from succeeding.

Workaround: None.