Updated obsolete FileTypeCheckStateIsDirty to the new name BeforeBackgroundFileCheck
Updated obsolete FileTypeCheckStateIsDirty to the new name BeforeBackgroundFileCheck

Missed this with the last PR for FSharp.Compiler.Service API changes.

fsharp/fsharpbinding,Ming-Tang/fsharpbinding,nosami/xamarin-monodevelop-fsharp-addin,nosami/xamarin-monodevelop-fsharp-addin,fsharp/fsharpbinding,fsharp/xamarin-monodevelop-fsharp-addin,fsharp/xamarin-monodevelop-fsharp-addin,Ming-Tang/fsharpbinding,fsharp/fsharpbinding,Ming-Tang/fsharpbinding