Update 1 NuGet dependencies

Author: github-actions[bot]

nanoFramework.WebServer.nuspec

@@ -27,7 +27,7 @@ Supports both HTTPS and HTTP.</description>
       <dependency id="nanoFramework.System.Collections" version="1.3.0" />
       <dependency id="nanoFramework.System.Text" version="1.1.3-preview.4" />
       <dependency id="nanoFramework.System.Net" version="1.8.0-preview.9" />
-      <dependency id="nanoFramework.System.Net.Http.Server" version="1.4.0-preview.5" />
+      <dependency id="nanoFramework.System.Net.Http.Server" version="1.4.0-preview.6" />
       <dependency id="nanoFramework.Windows.Storage" version="1.4.6-preview.5" />
       <dependency id="nanoFramework.Windows.Storage.Streams" version="1.12.4-preview.3" />
     </dependencies>

nanoFramework.WebServer/nanoFramework.WebServer.nfproj

@@ -65,7 +65,7 @@
       <Private>True</Private>
     </Reference>
     <Reference Include="System.Net.Http, Version=1.4.0.0, Culture=neutral, PublicKeyToken=c07d481e9758c731">
-      <HintPath>..\packages\nanoFramework.System.Net.Http.Server.1.4.0-preview.5\lib\System.Net.Http.dll</HintPath>
+      <HintPath>..\packages\nanoFramework.System.Net.Http.Server.1.4.0-preview.6\lib\System.Net.Http.dll</HintPath>
       <Private>True</Private>
     </Reference>
     <Reference Include="System.Threading, Version=1.0.3.3, Culture=neutral, PublicKeyToken=c07d481e9758c731">

nanoFramework.WebServer/packages.config

@@ -4,7 +4,7 @@
   <package id="nanoFramework.Runtime.Events" version="1.10.0-preview.1" targetFramework="netnanoframework10" />
   <package id="nanoFramework.System.Collections" version="1.3.0" targetFramework="netnanoframework10" />
   <package id="nanoFramework.System.Net" version="1.8.0-preview.9" targetFramework="netnanoframework10" />
-  <package id="nanoFramework.System.Net.Http.Server" version="1.4.0-preview.5" targetFramework="netnanoframework10" />
+  <package id="nanoFramework.System.Net.Http.Server" version="1.4.0-preview.6" targetFramework="netnanoframework10" />
   <package id="nanoFramework.System.Text" version="1.1.3-preview.4" targetFramework="netnanoframework10" />
   <package id="nanoFramework.System.Threading" version="1.0.3" />
   <package id="nanoFramework.Windows.Storage" version="1.4.6-preview.5" targetFramework="netnanoframework10" />