Bump Microsoft.AspNetCore.Hosting.WindowsServices from 3.1.7 to 3.1.8

Bumps [Microsoft.AspNetCore.Hosting.WindowsServices](https://github.com/aspnet/AspNetCore) from 3.1.7 to 3.1.8.
- [Release notes](https://github.com/aspnet/AspNetCore/releases)
- [Commits](dotnet/aspnetcore@v3.1.7...v3.1.8)

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

Rnwood.Smtp4dev/Rnwood.Smtp4dev.csproj

@@ -22,7 +22,7 @@
 		<PackageReference Include="CommandLiners.MonoOptions" Version="1.0.36" />
 		<PackageReference Include="HtmlAgilityPack" Version="1.11.24" />
 		<PackageReference Include="MailKit" Version="2.8.0" />
-		<PackageReference Include="Microsoft.AspNetCore.Hosting.WindowsServices" Version="3.1.7" />
+		<PackageReference Include="Microsoft.AspNetCore.Hosting.WindowsServices" Version="3.1.8" />
 		<PackageReference Include="Microsoft.AspNetCore.SignalR" Version="1.1.0" />
 		<PackageReference Include="Microsoft.AspNetCore.SignalR.Core" Version="1.1.0" />
 		<PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="2.2.0" />