Bump System.Net.Http from 2.0.20710.0 to 4.3.4 in /sdk

Bumps System.Net.Http from 2.0.20710.0 to 4.3.4.

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

Author: dependabot[bot]

sdk/aliyun-tablestore-sdk.csproj

@@ -22,7 +22,7 @@
     <PackageReference Include="Bosima.Google.ProtocolBuffers" Version="1.0.1" />
     <PackageReference Include="Google.Protobuf.Tools" Version="3.6.1" />
     <PackageReference Include="KdSoft.FlatBuffers" Version="1.12.0" />
-    <PackageReference Include="System.Net.Http" Version="2.0.20710" />
+    <PackageReference Include="System.Net.Http" Version="4.3.4" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
     <PackageReference Include="System.Net.Http">
@@ -31,7 +31,7 @@
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFramework)' == 'net40'">
     <PackageReference Include="System.Net.Http">
-      <Version>2.0.20710</Version>
+      <Version>4.3.4</Version>
     </PackageReference>
   </ItemGroup>
 </Project>