CP-13694: Add update URL configuration from reg
CP-13694: Add update URL configuration from reg

Signed-off-by: Cheng Zhang <f157832f2f1df5a7c962d3abb092f6b1ea020882@citrix.com>

kostaslamda/win-xenguestagent,xenserver/win-xenguestagent,kostaslamda/win-xenguestagent,xenserver/win-xenguestagent