Updating BuildTools from 2.1.0-preview2-15738 to 2.1.0-preview2-15739
Updating BuildTools from 2.1.0-preview2-15738 to 2.1.0-preview2-15739

[auto-updated: buildtools]

aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore