build.cake: fix an error (#492)
build.cake: fix an error (#492)

Error: Error(s) occurred when compiling build script:
.build/build.cake(82,42): error CS1503: Argument 2: cannot convert from 'bool' to 'Cake.Common.IO.DeleteDirectorySettings'

xabre/xamarin-bluetooth-le,fozzzgate/xamarin-bluetooth-le