Merge pull request #32 from launchdarkly/eb/ch21087/framework-refs

change package references to framework references for System assemblies

Author: eli-darkly

src/LaunchDarkly.EventSource/LaunchDarkly.EventSource.csproj

@@ -23,8 +23,8 @@
   <ItemGroup Condition=" '$(TargetFramework)' == 'net45' ">
     <Reference Include="System" />
     <Reference Include="Microsoft.CSharp" />
-    <PackageReference Include="System.Runtime" Version="4.3.0" />
-    <PackageReference Include="System.Net.Http" Version="4.3.2" />
+    <Reference Include="System.Runtime" />
+    <Reference Include="System.Net.Http" />
   </ItemGroup>
 
   <ItemGroup>