Fixed generation of release notes during build

Author: Chris Martinez

build/nuget.targets

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 
- <Target Name="GenerateReleaseNotes" AfterTargets="BeforeBuild" Label="NuGet">
+ <Target Name="GenerateReleaseNotes" BeforeTargets="GenerateNuspec" Label="NuGet">
 
   <PropertyGroup>
    <ReleaseNoteCount>@(ReleaseNotes->Count())</ReleaseNoteCount>