Update 1 NuGet dependencies

Author: github-actions[bot]

nanoFramework.Azure.Devices.Client.nuspec

@@ -27,7 +27,7 @@ This is an SDK for Azure IoT Hub using MQTT broker.</description>
       <dependency id="nanoFramework.Runtime.Native" version="1.5.4-preview.3" />
       <dependency id="nanoFramework.System.Collections" version="1.4.0-preview.12" />
       <dependency id="nanoFramework.System.Net" version="1.8.0-preview.19" />
-      <dependency id="nanoFramework.System.Net.Http" version="1.4.0-preview.16" />
+      <dependency id="nanoFramework.System.Net.Http" version="1.4.0-preview.18" />
       <dependency id="nanoFramework.System.Text" version="1.1.3-preview.11" />
       <dependency id="nanoFramework.System.Threading" version="1.0.4-preview.12" />
       <dependency id="nanoFramework.Windows.Storage.Streams" version="1.12.4-preview.12" />

nanoFramework.Azure.Devices.Client/Azure.Devices.Client.nfproj

@@ -89,7 +89,7 @@
       <Private>True</Private>
     </Reference>
     <Reference Include="System.Net.Http, Version=1.4.0.0, Culture=neutral, PublicKeyToken=c07d481e9758c731">
-      <HintPath>..\packages\nanoFramework.System.Net.Http.1.4.0-preview.16\lib\System.Net.Http.dll</HintPath>
+      <HintPath>..\packages\nanoFramework.System.Net.Http.1.4.0-preview.18\lib\System.Net.Http.dll</HintPath>
       <Private>True</Private>
     </Reference>
     <Reference Include="System.Threading, Version=1.0.4.0, Culture=neutral, PublicKeyToken=c07d481e9758c731">

nanoFramework.Azure.Devices.Client/packages.config

@@ -7,7 +7,7 @@
   <package id="nanoFramework.Runtime.Native" version="1.5.4-preview.3" targetFramework="netnanoframework10" />
   <package id="nanoFramework.System.Collections" version="1.4.0-preview.12" targetFramework="netnanoframework10" />
   <package id="nanoFramework.System.Net" version="1.8.0-preview.19" targetFramework="netnanoframework10" />
-  <package id="nanoFramework.System.Net.Http" version="1.4.0-preview.16" targetFramework="netnanoframework10" />
+  <package id="nanoFramework.System.Net.Http" version="1.4.0-preview.18" targetFramework="netnanoframework10" />
   <package id="nanoFramework.System.Text" version="1.1.3-preview.11" targetFramework="netnanoframework10" />
   <package id="nanoFramework.System.Threading" version="1.0.4-preview.12" targetFramework="netnanoframework10" />
   <package id="nanoFramework.Windows.Storage.Streams" version="1.12.4-preview.12" targetFramework="netnanoframework10" />