fix fsc binding redirect
fix fsc binding redirect

the 'System.Collections.Immutable' referenced by fsc is 1.2.0.0 and is also the one
contained inside the nupkg

dsyme/FSharp.Compiler.Service,Jand42/FSharp.Compiler.Service,cloudRoutine/FSharp.Compiler.Service,dsyme/FSharp.Compiler.Service,fsharp/fsharp,cloudRoutine/FSharp.Compiler.Service,dsyme/FSharp.Compiler.Service,fsharp/fsharp,sergey-tihon/FSharp.Compiler.Service,sergey-tihon/FSharp.Compiler.Service,cloudRoutine/FSharp.Compiler.Service,ncave/FSharp.Compiler.Service,ncave/FSharp.Compiler.Service,fsharp/fsharp,sergey-tihon/FSharp.Compiler.Service,Jand42/FSharp.Compiler.Service,ncave/FSharp.Compiler.Service,Jand42/FSharp.Compiler.Service