Bump System.Net.Http from 4.3.2 to 4.3.4 in /test

Bumps System.Net.Http from 4.3.2 to 4.3.4.

Signed-off-by: dependabot[bot] <support@github.com>

test/autorest.azureresourceschema.test.csproj

@@ -33,7 +33,7 @@
     <PackageReference Include="xunit" Version="2.2.0" />
     <PackageReference Include="System.Reflection.TypeExtensions" Version="4.3.0" />
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="2.0.0-rc2" />
-    <PackageReference Include="System.Net.Http" Version="4.3.2" />
+    <PackageReference Include="System.Net.Http" Version="4.3.4" />
     <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.3" />
   </ItemGroup>