[NWD] Upgrade System.Net.Http

Part of: b/228778281
Part of: b/228778704
Part of: b/228778767
Part of: b/228778805
Part of: b/228778322

Change-Id: Ia72fb4c1ffa9701f4a95fe23633f7be3ede63f7b
Reviewed-on: https://gnocchi-internal-review.git.corp.google.com/c/third_party/epplus/+/228800
Reviewed-by: Trevor Ryland <tryland@google.com>

NetCoreTests/NetCoreTests.csproj

diff --git a/NetCoreTests/NetCoreTests.csproj b/NetCoreTests/NetCoreTests.csproj
index 9af6cc5..1b192e1 100644
--- a/NetCoreTests/NetCoreTests.csproj
+++ b/NetCoreTests/NetCoreTests.csproj
@@ -8,7 +8,7 @@
     <PackageReference Include="MSTest.TestAdapter" Version="2.2.8"/>
     <PackageReference Include="MSTest.TestFramework" Version="2.2.8"/>
     <PackageReference Include="Microsoft.NET.Test.SDK" Version="17.1.0"/>
-
+    <PackageReference Include="System.Net.Http" Version="4.3.4" />
     <ProjectReference Include="..\EPPlus\EPPlusSDK.csproj"/>
 
     <None Include="TestWorkbooks/**" CopyToOutputDirectory="PreserveNewest"/>