Elasticsearch.Net v6.5.0 is broken (see elastic/elasticsearch-net#3582)

Author: AndrewKostousov

RemoteTaskQueue.Monitoring/RemoteTaskQueue.Monitoring.csproj

@@ -99,7 +99,7 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Elasticsearch.Net">
-      <Version>6.5.0</Version>
+      <Version>6.4.0</Version>
     </PackageReference>
     <PackageReference Include="Newtonsoft.Json">
       <Version>12.0.1</Version>