Fixed a error in NuGet/build-package.cmd file

Author: Taritsyn

NuGet/build-package.cmd

@@ -2,7 +2,7 @@ set project_name=MsieJavaScriptEngine
 set net4_project_source_dir=..\src\%project_name%.Net4
 set net4_project_bin_dir=%net4_project_source_dir%\bin\Release
 set dotnet_project_source_dir=..\src\%project_name%
-set dotnet_project_bin_dir=%project_source_dir%\bin\Release
+set dotnet_project_bin_dir=%dotnet_project_source_dir%\bin\Release
 set licenses_dir=..\Licenses
 set net40_msbuild="\Windows\Microsoft.NET\Framework\v4.0.30319\msbuild.exe"
 set dotnet_cli="%ProgramFiles%\dotnet\dotnet.exe"