Use JSInterop package that we produce from Extensions

eng/Versions.props

@@ -156,7 +156,6 @@
     <MicrosoftAspNetCoreBlazorMonoPackageVersion>0.8.0-preview1-20181126.1</MicrosoftAspNetCoreBlazorMonoPackageVersion>
     <!-- When updating this, ensure you also update src/Components/Browser.JS/src/package.json to reference the corresponding version of @dotnet/jsinterop -->
     <MonoWebAssemblyInteropPackageVersion>0.8.0-preview1-20181126.4</MonoWebAssemblyInteropPackageVersion>
-    <MicrosoftJSInteropPackageVersion>0.8.0-preview1-20181126.4</MicrosoftJSInteropPackageVersion>
 
     <!-- 3rd party dependencies -->
     <AngleSharpPackageVersion>0.9.9</AngleSharpPackageVersion>